Recently in the Insects Category

Jeffrey Hahn, Asst. Extension Entomologist

Be on the watch for eastern tent caterpillars.  There was a report of these insects at the end of last week in southeast Minnesota and it was reported in the Twin Cities at the beginning of this week.  The caterpillars are bluish black with yellow and a white stripe running the length of the top of its body. They are also mostly smooth except for a series of hairs sticking out along the sides of their bodies. They are two inches long when fully grown. 

However, the first sign you'll notice are the silken tents they create in the forks of branches.  After the caterpillars first hatch, they'll construct this webbing which serves as a shelter they use at night and during rainy weather.  The tent will be small at first but will increase in size and can eventually become quite conspicuous.  During the day they crawl out of these tents and feed on tree leaves.  Although they are found on a variety of hardwood trees, eastern tent caterpillars are particularly fond of fruit trees, including apple, chokecherry, crabapple, plum, and cherry.

Healthy, well-established trees can tolerate eastern tent caterpillar feeding.   Their feeding, as well as the presence of their webs, is just a cosmetic problem and only affects the trees' appearance.  However, young trees, as well as unhealthy, stressed trees, are more susceptible to feeding damage and should be protected.  

Also consider the size of the caterpillars.  As long as they are no more than half their full grown size, i.e. one inch or less, it is worth considering whether to treat them.  This is not an issue now as they are just emerging and they are all small.  However, if an infestation is discovered later, it is important to check to make sure they are not too large (larger than an inch).  The larger they are, the closer they are to being done feeding and then it is not worthwhile to treat them.

A great non-chemical method to deal with eastern tent caterpillars is to wait until they have retreated back to their webbing at the end of the day or on a rainy day and then pull out the webbing, along with the caterpillars.  Then bury or bag them to properly dispose of them (you could burn them if it is permitted where you live).

There are a variety of residual insecticides that you can use if it is desirable to protect your trees.  Consider using products that have a low impact on the environment, such as Bacillus thuringiensis, spinosad, and insecticidal soap.  Bacillus thuringiensis is a particularly good product if the tree is flowering since it will not harm visiting honey bees.  If you use insecticidal soap, the product needs to directly contact the insects.  There is no residual activity so you may need to repeat the treatment.

Jeffrey Hahn, Asst. Extension Entomologist

We have endured a long cold spring but now the weather is finally getting warmer so it is enjoyable to be outside again.  Finally, we are ready to enjoy our favorite outdoor activities.  You definitely want to get outside but with the return of nice weather also come ticks.  Take the proper precautions and protect yourself from these pests.

The two most common ticks in Minnesota are American dog ticks (also called wood ticks) and blacklegged ticks (formerly called deer ticks).  While American dog ticks are not important vectors of disease in Minnesota, they are nuisances because they bite us (also dogs too!).  Blacklegged ticks are also nuisances but they can be potentially more serious as they transmit diseases, including Lyme disease, anaplasmosis, babesosis, and Powassan encephalitis to people in Minnesota.  Of these, Lyme disease is the most common.

You are most likely going to encounter ticks in tall, grassy areas and in the undergrowth of hardwood forests so avoid those areas when possible.  When you are out in areas where ticks are known to occur, one of the best methods of protecting yourself is the use of a repellent.  You can apply DEET to both skin and clothes, while products containing permethrin should only be applied to clothes.  It is also very important to check yourself for ticks after coming back inside.  The sooner, you can find any ticks that may have crawled onto you, the sooner you can remove them, hopefully before they have started to bite you.  Ticks can't transmit disease if they are not biting.

For more information, see Ticks and their Control and Tick-borne diseases in Minnesota.

Jeffrey Hahn, Asst. Extension Entomologist

The following is from a news release that was issued on May 2, 2013

The United States Department of Agriculture (USDA) and the U.S. Environmental Protection Agency (EPA) released a comprehensive report last week on honey bee health. The report states that there are multiple factors playing a role in honey bee colony declines, including parasites and disease, genetics, poor nutrition and pesticide exposure.

In October 2012, a National Stakeholders Conference on Honey Bee Health, led by federal researchers and managers, along with Pennsylvania State University, was convened to synthesize the current state of knowledge regarding the primary factors that scientists believe have the greatest impact on managed bee health.

Key findings include:

Parasites and Disease Present Risks to Honey Bees:
• The parasitic Varroa mite is recognized as the major factor underlying colony loss in the U.S. and other countries. There is widespread resistance to the chemicals beekeepers use to control mites within the hive. New virus species have been found in the U.S. and several of these have been associated with Colony Collapse Disorder (CCD).

Increased Genetic Diversity is Needed:
• U.S. honeybee colonies need increased genetic diversity. Genetic variation improves bees thermoregulation (the ability to keep body temperature steady even if the surrounding environment is different), disease resistance and worker productivity.
• Honey bee breeding should emphasize traits such as hygienic behavior that confer improved resistance to Varroa mites and diseases (such as American foulbrood). 

Poor Nutrition Among Honey Bee Colonies:
• Nutrition has a major impact on individual bee and colony longevity. A nutrition-poor diet can make bees more susceptible to harm from disease and parasites. Bees need better forage and a variety of plants to support colony health.
• Federal and state partners should consider actions affecting land management to maximize available nutritional forage to promote and enhance good bee health and to protect bees by keeping them away from pesticide-treated fields.

There is a Need for Improved Collaboration and Information Sharing:
• Best Management Practices associated with bees and pesticide use, exist, but are not widely or systematically followed by members of the crop-producing industry. There is a need for informed and coordinated communication between growers and beekeepers and effective collaboration between stakeholders on practices to protect bees from pesticides.
• Beekeepers emphasized the need for accurate and timely bee kill incident reporting, monitoring, and enforcement.

Additional Research is Needed to Determine Risks Presented by Pesticides:
• The most pressing pesticide research questions relate to determining actual pesticide exposures and effects of pesticides to bees in the field and the potential for impacts on bee health and productivity of whole honey bee colonies.

Those involved in developing the report include USDA's Office of Pest Management Policy (OPMP), National Institute of Food and Agriculture (NIFA), Agricultural Research Services (ARS), Animal and Plant Health Inspection Service (APHIS), Natural Resource Conservation Service (NRCS) as well as the EPA and Pennsylvania State University. The report will provide important input to the Colony Collapse Disorder Steering Committee, led by the USDA, EPA and the National Agricultural Statistics Service (NASS).

An estimated one-third of all food and beverages are made possible by pollination, mainly by honey bees. In the United States, pollination contributes to crop production worth $20-30 billion in agricultural production annually. A decline in managed bee colonies puts great pressure on the sectors of agriculture reliant on commercial pollination services. This is evident from reports of shortages of bees available for the pollination of many crops.

The Colony Collapse Steering Committee was formed in response to a sudden and widespread disappearance of adult honey bees from beehives, which first occurred in 2006. The Committee will consider the report's recommendations and update the CCD Action Plan which will outline major priorities to be addressed in the next 5-10 years and serve as a reference document for policy makers, legislators and the public and will help coordinate the federal strategy in response to honey bee losses.

To view the report, which represents the consensus of the scientific community studying honey bees, please visit: http://www.usda.gov/documents/ReportHoneyBeeHealth.pdf

Jeffrey Hahn, Asst. Extension Entomologist

Small, fly-like insects have been appearing in people's homes this spring, especially around windows.  Although they look like gnats or flies (one person thought they looked like fleas), these insects are hackberry psyllids.  Despite their similarity to flies, these insects are more closely related to aphids and leafhoppers (they actually look like tiny cicadas).

Psyllids are about 1/8 inch long with a somewhat compact body.  Their wings, a mottled brown with small black and white spots, fold up tent-like over their backs.  During the spring and summer, they are associated with hackberry trees where they are gall producers on leaves.  Adults emerge from their galls in the fall.  Soon after that, they seek shelter to protect themselves from the winter; many end up in homes and other buildings, similar to boxelder bugs and lady beetles.

After they move into various cracks and spaces around the exterior of homes, psyllids remain dormant during the winter.  As warm weather arrives in the spring, many of them become trapped inside homes as they become active (they can also emerge inside buildings during mild winter days).  Fortunately, they do not live long indoors.  They also do not reproduce inside buildings; the individuals you see in the spring have been inside your home since fall.  They are harmless and just a nuisance. 

When you see psyllids in the spring, the only necessary control is physical removal.  Eventually they will either die inside or find a way to get outside.  In either case, this problem will be over this soon.  For more information about psyllids, including steps you can take in the fall to help prevent their entry into your home, see our publication on hackberry psyllids.  

Jeffrey Hahn, Asst. Extension Entomologist

Some residents have recently been experiencing problems with wasps in their homes. The first reaction they generally have is that they have an active nest somewhere in their building. However, what people are actually seeing are just queens that have been hibernating since last fall.

The old queen and all the workers die when freezing temperatures arrive in the fall; nothing is left alive in the nests. The only survivors are new queens that are produced at the end of summer. They leave their colonies and look for places to spend the winter. That could be under loose bark, under leaves, in or under logs, or in the cracks and crevices of buildings. Wasp queens usually overwinter individually. However, paper wasp queens tend to overwinter gregariously.

People can rest assured that if they see wasps in their buildings now, even if there are a lot of them, they are not nesting in their homes. The wasps are just overwintering insects that become active with warmer spring weather, like a boxelder bug or a lady beetle.

All the queens will eventually become active and either find their way outside or become trapped indoors. When you find wasps in your home at this time of the year, the best control is to physically remove them as you see them. They are generally sluggish when they first become active so you should be able to dispose of them with less risk of being stung.

To minimize this problem next year, it is important to seal up as many potential entry points around the outside of your home as possible. This can be supplemented with an insecticide treatment around the exterior during late summer or early fall. If this is difficult task for a homeowner, they can hire a pest management professional (pest control operator) to do this job.

Jeffrey Hahn, Asst. Extension Entomologist

Two invasive insect pests, emerald Ash Borer (EAB) and brown marmorated stink bug (BMSB) were found in new locations during March.

EAB was discovered in Roseville (Ramsey County) on March 19 at the intersection of Snelling Ave. and Highway 36 by an arborist. The Minnesota Dept. of Agriculture (MDA) was contacted and after inspecting the tree was able to confirm one ash was infested by EAB. They also found three nearby trees that exhibited EAB symptoms and is suspected to be infested. MDA and the city of Roseville will conduct additional surveys in the area to verify the extent of the infestation. So far, the infestation only appears to be a few years old and likely represents a new pocket of infestation.

Despite this new infestation, EAB has still been confirmed in only four counties in Minnesota. In addition to Ramsey County, EAB has also been identified in Hennepin, Winona, and Houston Counties. You can use this MDA map to see where EAB has been confirmed in Minnesota.  For more information on EAB, see the Extension emerald ash borer page.

In early March, BMSB was confirmed in Duluth (St. Louis County). A student working in the University of Minnesota Duluth insect collection found a stink bug that looked suspiciously like a BMSB. The specimen was brought to the attention of the collection's curator. She e-mailed pictures of the specimen to entomologists at the MDA and the University of Minnesota. The entomologists at both institutions confirmed the specimen was indeed BMSB. The insect had been originally collected in January, 2011, inside a home in Duluth.

So far, BMSB is not very common in Minnesota and all of the specimens of this insect have been discovered in homes during winter. The Duluth find is the furthest north this insect has been found in Minnesota. BMSB has been found primarily in the Twin Cities area (Anoka, Carver, Chisago, Dakota, Hennepin, Ramsey, Washington Counties) as well as in the southeast corner of the state (Winona County). For more information on BMSB, see the MDA fact sheet.

If you believe you have discovered an insect that is a brown marmorated stink bug or a spotted wing drosophila report it to the Minnesota Dept. of Agriculture at 888- 545-6684 or Arrest.The.Pest@state.mn.us.

Karl Foord - Extension Educator, Horticulture

At a recent conference on high tunnel horticulture we received an update on biological control from Carol Glenister, the president of IPM Laboratories. IPM Laboratories supplies and supports the successful use of healthy beneficial organisms for the biological control of pests.

Carol has coined the term "guardian plants" that function in the following ways: 1) are more attractive to the pest species than the crop being grown i.e. 'indicator' or 'trap' plants, 2) provide forage for natural enemies of the pests i.e. 'habitat' plants, and 3) provide forage for non-pest prey species that serve as an additional food source for natural enemies or serves as a reproductive site for natural enemies i.e. 'banker' plants.

The indicator plants let you know the pest is present and the habitat and banker plants provide resources that encourage the natural enemies to remain and thrive on site.

In natural populations the predator numbers shadow the prey numbers, but the prey species always reproduce more rapidly so there is often a delay in control. If the control comes after the prey has damaged our plants then the predator hasn't benefited our production system. If the two-spotted spider mites are finally controlled by the predatory mites but your tomatoes performed poorly during the battle, there is little cause for celebration. The key is to have predator numbers in sufficient quantity early in development to keep prey damage below an acceptable threshold.

This means knowing what pest you expect to encounter, placing the proper indicator plants, monitoring for pest activity, getting predator species in a timely fashion, providing habitat plants and tracking pest and prey activity and numbers.

Natural enemies such as the following are presently being used to control whiteflies in greenhouses; two parasitoid wasps (Encarsia formosa Photos 1 - 4, and Eretmocerus eremicus Photo 5), and a small lady bird beetle (Delphastus catalinae) Photo 6. Note the incredibly small size of these insects - less than 1 mm in length.

In one experiment Lantana was used as a guardian plant among herbs such as oregano and lemon verbena, and the Encarsia formosa wasp was used as the prey species. The ratio of whitefly pests found on Lantana to those on the herbs was 79 to 1. The whitefly pest was drawn to the trap plant where it met its demise at the "hands" of the Encarsia wasp. This experiment can be viewed in greater detail at http://www.ipmlabs.com/whitefly-predators/plant-pests/whiteflies/biological-controls/

There is a great deal of research being conducted in this area, especially on the functioning of these bio-control organisms in outdoor environs. Consider the number of organisms functioning as parasitoids, predators, and pathogens as noted in Tables 1 - 3.

This is a fascinating research arena and one worth tracking advancements.

Jeffrey Hahn, Asst. Extension Entomologist

Winter is not a time when you typically expect to encounter ants in your home. However, it happens more often than you might think. One of the more common ants found in homes and other buildings is pavement ants. This ant is 1/8th inch long and is reddish brown, although it can range in color from light brown to dark brown to almost black. With magnification you can see that this ant has a two-segmented petiole (the waist between the thorax and the abdomen) and two short spines projecting from the thorax.

Pavement ants like to nest in the soil under or besides objects, such as stones, bricks, sidewalks, and driveways. They can also nest under the concrete slabs of homes as well as in wall voids. They typically nest near a heating source which allows the ants to be active during winter. They can follow pipes that go through slab to move up into the living quarters of homes thorough expansion joints, under baseboards and floor registers. Sometimes large numbers of winged pavement ants are found which are the reproductives of the colony, i.e. females and males.

Pavement ants can infest foods; they like protein and grease, such as meats, cheese, dead insects, dry pet food, and peanut butter, as well as a variety of sweets. Other than that, pavement ants are mostly annoying and are not particularly damaging to homes.

If you are finding pavement ants in your home, try to determine from where they entering. If you can determine they are moving through a crack, e.g. in an expansion joint, try to seal it to help keep pavement ants out. If you are not able to find how they are getting into your home, then try baiting them.

Select a bait that is effective for grease feeding ants and place it where you are commonly finding them. Don't be surprised if there is an increase in the number of workers that are around the bait. That's good, the more ants that take bait back to the nest, the more likely you can eliminate it. Don't spray the foraging workers. It doesn't have any impact on the colony and will also lessen the ability of the workers to take bait back to the nest.

If you are not successful in your efforts to get rid of pavement ants or you would rather have someone control them for you from the start, talk to a professional pest management service about treating your ants.

Not all ants found indoors during winter will be pavement ants. People can also potentially see carpenter ants, Pharaoh ants, yellow ants, and thief ants in their homes during the winter. Their habits differ as do the methods for treating them. If you have any doubt as to what kind of ant problem you have, get them identified them by an expert.

The Minnesota Fruit and Vegetable First Detector Program is a new joint program between the University of Minnesota Extension and the Minnesota Department of Agriculture to increase awareness and detection of invasive diseases and insect pests of fruits and vegetables. There are two ways that you can be involved.

1. Attend a workshop about invasive pests that threaten Minnesota fruit and vegetables. Learn how to identify invasive pests and distinguish them from common look a likes. Find out the proper steps to take if you suspect you have found and invasive pest.
2. Become a first detector volunteer. Act as a local resource to help state officials respond to calls made to the Arrest a Pest Hotline. First Detectors are volunteers trained to help citizens diagnose and report possible infestations of invasive species to the Minnesota Department of Agriculture. First Detectors are a part of the National Plant Diagnostic Network (NPDN) First Detector Program which promotes the early detection of invasive plant pathogens, arthropods, nematodes and weeds.

Michelle Grabowski and Jeff Hahn, UMN Extension

The ground is cold, trees have dropped their leaves, and perennial and annual flowering plants have died back to the ground. Yet there is still time for a garden clean up that will reduce the number of pathogens and insect pests that survive from this season to the next. Sanitation, the removal of a infected plant material, is one of the basic steps of integrated pest management. It is a chemical free way to reduce pest damage in future growing seasons.

For sanitation to work you must remove the part of the plant that is infected with a pathogen or insect pest completely from the area and destroy it. Disease infected plant material can be burned, buried or composted. Check with local laws about burning plant material. Composting will kill pathogens and insects only if the pile gets hot. If your backyard compost pile is a slow pile of cold rot, consider taking infected material to a municipal compost site. These sites have so much plant residue to work with they manage the pile to heat up so the material breaks down quickly. It is important to realize that it might take a few years of good sanitation to truly get ahead of a fungal or bacterial plant disease. Fungi are known to survive 2-4 years in buried plant debris, bacteria typically can survive 1-2 years.

Here is a list of a few plant problems that would benefit from fall sanitation efforts.

Trees and Shrubs
Apple Scab on crabapple or apple trees
Black Spot on rose
Any leaf spot disease like tar spot on maple, anthracnose or linden leaf blotch
Rake up and remove those leaves or they will produce fungal spores to start next years epidemic!

In the Flower Garden
Fungal and bacterial leaf spot diseases on perennials like Botryis leaf spot on Peony, Daylily leaf streak, Iris leaf spot. Sorry but sanitation will not help reduce powdery mildew.
Remove plants at ground level. Clean up all stems and fallen leaves. The pathogens survive in any infected plant material.

Four Lined Plant Bug
Iris Borer
These insects lay eggs on plant material late in the growing season. In spring the new insects cause damage on these plants.

In the Vegetable Garden
Septoria Leaf Spot on tomato
Early Blight on Tomato
Bacterial leaf spot on pepper
Remove plants at ground level. Clean up all stems, fallen leaves, and rotten fruit. Infected plant material can be removed from the garden or tilled under.

Squash Bug
Asparagus Beetles
These insects spend the winter as adults under plant debris. By removing plant debris in general the number of overwintering sites for these insects is reduced.

Jeffrey Hahn, Asst. Extension Entomologist

The resurgence of bed bugs in the U.S. over the last 10 or so years has increased many people's awareness of these biting insects. They have presented residents and pest management professionals a tremendous challenge to detect and eliminate them. A popular tactic used by residents in bed bug control is the application of total release foggers, also known as bug bombs. Many people have turned to these products to help them control their bed bug problems. But are they effective? This question was examined in a research study conducted by Drs. Susan Jones and Joshua Bryant at Ohio State University.

They compared three popular bug bombs that are available to residents. The Hot Shot Bedbug and Flea Fogger is specifically labeled for control of bed bugs and was more extensively tested. They also examined the Spectracide Bug Stop Indoor Fogger and Eliminator Indoor Fogger. Although these products are not listed specifically for bed bugs, they are labeled for flying and crawling insects and could be used by Minnesotans in an attempt to eliminate bed bugs.

Jones and Bryant tested these products against five different populations of bed bugs collected from home infestations in Ohio. They also tested these bug bombs against a strain of bed bugs that has been reared exclusively in a laboratory for 39 years. These bed bugs have never been exposed to pesticides and are susceptible to bed bug products. All of these bed bugs were exposed to the Hot Shot Fogger in three scenarios, direct exposure, optional harborage (they could hide under filter paper), and forced harborage (they were covered by a thin fabric covering). The other two foggers were used only in direct exposure and optional harborage experiments (they were unable to complete the Eliminator Fogger and optional harborage trial) against two of the field collected bed bugs as well as the continuously lab reared bed bugs.

All three bug bombs had generally little effect on the 'wild' collected bed bugs in the direct exposure experiment (with one moderate exception). However, most or all of the lab reared bed bugs were killed. Similar results were seen in the optional harborage experiment except that it took longer to kill most or all of the lab reared bed bugs. In the forced harborage trial, all bed bugs, including the susceptible lab reared bed bugs, were minimally affected by the Hot Shot Fogger.

So what does all of this mean? The short answer is that bug bombs are not effective in controlling bed bugs. There are several reasons why this is true. First, the bed bugs that we battle in our homes are generally not affected by the insecticides contained in bug bombs, even if they are directly exposed to them. There has been growing evidence of varying degrees of bed bug resistance (i.e. they are much less vulnerable) to pyrethroid insecticides which is the primary active ingredient of bug bombs. Only bed bugs that have never been exposed to insecticides could be easily killed and then only if they were directly exposed or were exposed before they sought a place to hide. This research project also concluded that bug bombs were ineffective because of short exposure times, the low concentration of insecticides, and the lack of residual activity.

Bug bombs are also not effective because the insecticide does not penetrate to the harborages where bed bugs hide. This is critically important as these biting insects spend most of their time hiding in cracks, tight spaces, behind and under objects, and similar places (up to 80% of them hide in harborages during the day). They are infrequently out in the open for any length of time and even then just a few at a time. For bug bombs to be effective, they need their target insect to be out in the open long enough for the insecticide to reach them. This research also found that even the susceptible populations of bed bugs were largely unaffected when they were in protected sites.

While bug bombs are not the answer, there are a lot of positive steps you can take to help control a bed bug infestation. See the University of Minnesota's Let's Beat the Bed Bug web page. From there you can access a variety of fact sheets and other sources of information as well how to contact the Bed Bug hotline.

The results of this research were published in the Journal of Economic Entomology, 105(3): 957-963 (2012).  A summary of this research was also published in Pest Control Technology in the October 2012 issue.

Jeffrey Hahn, Asst. Extension Entomologist

Termites are present in Minnesota but they are not common. They are found in southern Minnesota up to about the Twin Cities area and very rarely discovered, if ever, in central and northern Minnesota. Minnesota's native termites are subterranean termites, Reticulitermes spp. They maintain colonies in the ground and attack wood that is contact with the soil. You rarely see the termites themselves because the bulk of them stay inside the colony while those that travel outside of it move about in mud tubes they construct so they can maintain the proper temperature and humidity they need to survive.

That is why the discovery of winged termites in a home in Minneapolis during September was so interesting and unusual. First, when termites swarm, i.e. winged forms leave the nest en masse, they do so in the spring (and this is very rarely seen in Minnesota). Even more interesting was when the termites were examined more closely, they were identified not as the local subterranean termites but as drywood termites. This group of termites is not native to Minnesota but is most commonly found along the costal areas of the southern U.S. from North Carolina to California.

At first, just a single winged termite was found at a window at this home. Shortly after that, about 100 were found behind a couch. In the next couple of weeks, dozens more were found either behind or under the couch. The resident had owned this piece of furniture for 14 years. She had purchased it in Minnesota and never lived outside of the upper Midwest with it. The resident had never received any items mailed from areas where drywood termites are native nor had she ever noticed termites or sawdust in her home before, especially around the couch.

This brought up several excellent questions: where did the termites come from; how long have they been in the couch; and have they spread into other areas of the house? Information about drywood termite biology helped to answer these questions.

Although the couch had never traveled to any drywood termite endemic areas after the homeowner bought it, it undoubtedly was built and/or stored in a warehouse somewhere in the south where these termites are native. It was there that the couch became infested. You wouldn't normally think that insects could infest a piece of furniture for 14 years without their presence being noticed but drywood termite colonies grow very slowly and it isn't unusual for them to take that long before they are mature enough to produce new queens. So it is extremely likely that the termites were in the couch when it was bought and had been in the furniture during that entire time the resident owned it. Because the termites were confined to the couch, they did not spread to other areas in the house.

Fortunately for the homeowner, the only necessary control was to remove the couch from her home. It was taken away by a local pest management company, heat treated to kill the termites, and then properly disposed of. All's well that ends well.

Jeffrey Hahn, Asst. Extension Entomologist

It has been a long summer but fall is finally catching up with us. Fall is also the time when nuisance insects fly to buildings and other structures to look for places to spend the winter. One insect to be on the watch for is the boxelder bug Although these orange and black insects are around every year, they have been particularly numerous this summer. The weather has a lot to do with that as years of hot, dry summers are very favorable for their development and we often experience much larger populations of them then.

Right now a lot of people are finding large numbers of boxelder bugs on the sides of their homes. Being on the outside of structures is not necessarily bad if boxelder bugs would just stay there but eventually many of these insects will get inside these buildings. There are not any practical home remedies for dissuading boxelder bugs from landing on homes, although people have tried solutions such as throwing boiling water on them and trying to kill them with fly swatters. While people may not like all of the boxelder bugs on the outside, people should aim at preventing these insects from getting into their homes.

Control is two fold. First, seal as many spaces and openings as possible that may allow boxelder bugs into your home. Concentrate around widows and doors, roof lines, where utility lines enter buildings, and where horizontal and vertical surfaces meet. Second, supplement this with a residual insecticide application, especially around areas where boxelder bugs are most likely to gain access. This is something homeowners can try themselves; common active ingredients that could be used would include permethrin and beta-cyfluthrin (make sure products are labeled for the outside of homes). Or they can contact an experienced pest management service to make this application for them.

Not only is it important to take action now to keep boxelder bugs out of your home this fall but a lot of these insects can also become nuisances later during days of mild winter temperatures. Once they get inside, they seek out wall voids, attics and other nooks and crannies in which to hibernate. It is important for boxelder bugs to find a place that is unheated and will remain cold during winter. As long as they are in such place, they will remain dormant.

However, as temperatures warm up the sites where boxelder bugs are hiding, they will wake up, 'thinking' spring has arrived. They will move towards the warmth and will end up being trapped indoors. Boxelder bugs typically aggregate in clusters; insects on the outer part of these clusters will become active first. This results in boxelder bugs emerging at different times. When boxelder bugs appear in the middle of the winter, it appears that they have been reproducing indoors, however what people are seeing are adults that entered their homes the previous fall. (Note: Boxelder bugs are occasionally observed laying eggs indoors. However, either immature boxelder bugs don't hatch from them or if they do the young bugs do not have food and do not live long. They certainly are not able to mature into adult bugs.)

The boxelder bugs that get inside your home can definitely be annoying; in fact the more there are the more bothersome they usually are. Fortunately, boxelder bugs are harmless to people. They may occasionally stain surfaces but are otherwise not damaging to property. Once they are in your home, you have few options to deal with them. The easiest solution is physical removal, such as with a vacuum cleaner. This may not always be helpful when boxelder bugs are really numerous, but that is still the best control. This is why the more you can prevent from entering your home during fall, the fewer you will deal with later.

Jeffrey Hahn, Asst. Extension Entomologist

Since the presence of spotted wing drosophila (SWD) Drosophila suzukii was first confirmed in Minneapolis at the beginning of August (see August 15, 2012 Yard and Garden News, ), there have many reports of this fruit fly in other parts of the state. As of the end of August, SWD has been confirmed in 11 counties and suspected in another three, ranging as far north and west as Alexandria (Douglas County) and down to the southeast corner of the state.

Although SWD was found for the first time this year, it is possible that it had been present in Minnesota a year or two earlier but at levels to low to be detected. Regardless of when it first appeared in Minnesota, it is likely that the abundance we experienced this year was the result of spring weather that literally carried up large numbers of SWD on storm fronts. We have seen a variety of other insects this year that were likely influenced by weather patterns blowing them up to Minnesota including insects that we would not normally see in such large numbers (e.g. variegated cutworm) and insects that normally don't occur in Minnesota all (e.g. genista broom moth)

SWD attacks many types of ripening, thin-skinned, soft fruit, especially cane fruit, like raspberries and blackberries, blueberries, strawberries, grapes, cherries, and plums. There has been some question about whether they will attack tomatoes but it is doubful tomatoes are attractive to them. If you have a garden with any of these fruits, there are not a lot of options for protecting them this late into the season. The primary control is treating the adults when they are first present to prevent them from laying eggs in the fruit. Once fruit is infested, you can not effectively treat the larvae as they are protected inside the produce. Infected fruit becomes soft and decays and sometimes becomes discolored. When you probe into the fruit, you can usually see the small white maggots that are responsible.

There are some cultural control steps you can take to help minimize SWD. First, pick the berries frequently when they are ripening. Remove and destroy any overripe or obviously infested fruit. Don't place infested produce into compost piles as they will likely be able to complete their life cycle and emerge as adults. It is better to place them in plastic bags tightly tied shut and thrown out. You could also place infested fruit in clear plastic bags and leave them in the sun; the heat should kill them if left out for 12 - 24 hours. You could also freeze them, making sure that the fruit is frozen for a long enough period to kill the maggots.  Burying is not a good option as adults can still emerge even when buried down to 12 inches.

Even fruit that looks fine could be infested. Use your discretion as to whether you save or dispose of this produce. Should you inadvertently eat infested fruit, ingesting the maggots is not harmful to people. Using apparently uninfested fruit for cooking should not be a problem; any flies that are present would not survive the process.

SWD overwinters as an adult. It is unclear whether they can survive a Minnesota winter. This fly was not detected in Wisconsin in 2011 after it had been first found there in 2010. That could bode well for us but time will tell what kind of a problem we will face with SWD. It will be important to set up traps and survey for them in 2013.

If you encounter flies or maggots in fruit that you suspect are SWD, contact the Minnesota Department of Agriculture's "Arrest the Pest" hotline at 1-888-545-6684 or Arrest.the.Pest@state.mn.us. Please note the location and date of collection for the specimen.

For more information on SWD, see also the University of Minnesota's VegEdge web page.

Bob Koch, Minnesota Department of Agriculture
Jeff Hahn and Eric Burkness, University of Minnesota

A new fruit pest, the spotted wing drosophila (SWD) (Drosophila suzukii), has arrived in Minnesota. This pest feeds on small fruits and stone fruits. The SWD is an invasive pest of Asian origin that was first detected in the continental United States in California in 2008 and has since spread to several western and eastern states. It was found in Minnesota in August, 2012.

The first two detections of this pest were made by members of the public who reported the flies to the Minnesota Department of Agriculture (MDA). First, a homeowner from Hennepin County contacted the MDA about some flies she found in a yeast-baited trap she placed near a raspberry patch. Days later, the MDA was contacted by a citizen who found an abundance of maggots in some wild raspberries picked in Ramsey County. The MDA quickly followed up on both of these reports to visit the sites, collect specimens and confirm the identity of this new pest. It is impressive that people noticed such a small fly (or maggot), realized that it could be a new invader, and knew to contact agricultural authorities regarding the finds. It goes to show how much people care about protecting our resources.

The SWD looks very similar to the small fruit flies you might occasionally see flying around overripe fruit on your kitchen counter. However, unlike these other flies, which typically feed on overripe or deteriorating fruits, the SWD feeds on healthy, intact, ripening fruits. In particular, the SWD will feed on thin-skinned, soft fruits such as raspberries, blackberries, blueberries, strawberries, grapes, plums and cherries.
The SWD is difficult to distinguish from other species of small flies. The SWD is a small fly, only 2 - 3 mm (1/12 - 1/8 inch) long, with yellowish-brown coloration and prominent red eyes. Male SWD have dark spots near the tips of the clear wings. Several other species of small flies with spots on their wings can easily be confused for SWD. Female SWD have few distinguishing characters and are even more difficult to identify. Larvae of SWD are white with a cylindrical body that tapers on both ends. To date, SWD is known to be an outdoor pest; fruit flies found indoors are likely to be a different species.

Female SWD use a saw-like egg laying structure to lay their eggs in ripening fruits. The larvae of the SWD then feed within the fruits causing brown, sunken areas. Sometimes the symptoms will not show until after the crops are harvested and sometimes not until the fruits are in possession of the consumers. In addition to the damage caused directly by the larvae, the feeding makes the fruits susceptible to infestation by other insects and rot fungi and bacteria. The larvae will then leave the fruits to pupate and later emerge as adults. Multiple generations of SWD can occur in a year, with populations building throughout the summer. The overwintering stage of the SWD is the adult; however, its ability to survive Minnesota winters remains unknown.

With this pest being so new to Minnesota and the United States, little is known about how big of an impact it will have and what management tactics will be most effective. The MDA will be working with the University of Minnesota (Extension and the Department of Entomology) to determine how widespread this pest is in Minnesota and to alert farmers and gardeners of its presence and potential impacts. The University of Minnesota will also be developing recommendations for management of this pest on Minnesota fruit crops. SWD could be particularly devastating to blueberry, raspberry and grape growers, but we will need more information on when the pest is active in Minnesota and how well it can survive our winter weather.

Extension programs from other states have suggested several items for consideration in management of this pest. Sanitation is an important consideration to lessen local buildup of SWD populations. Sanitation practices include frequent harvest of crop to ensure ripe fruits are not in field for extended period of time and removal and destruction of old fruit remaining on stems and fallen fruit. Furthermore, crops can be monitored with traps baited with yeast or vinegar; however, yeast-baited traps appear more effective. Traps should be checked frequently (at least weekly) to determine the presence and abundance of SWD males and females. Monitoring for activity of SWD adults is also important, because once eggs are laid in the fruits it will be too late for other management tactics (for example, insecticides) to be effective. If SWD are found in the traps, an insecticide that is registered for use in the specific crop and effective against the pest should be applied. University of Minnesota Extension is evaluating what insecticide options will be effective in Minnesota. After treatment, monitoring of SWD should continue, with additional timely treatments applied as needed.

The adult flies are difficult to distinguish from other small flies; however, if you find an abundance of small, white maggots in what were apparently healthy fruits at the time of harvest, contact the MDA's "Arrest the Pest" hotline at 1-888-545-6684 or at Arrest.the.Pest@state.mn.us.  For more information, and SWD updates, please see the University of Minnesota SWD Web page.

Jeffrey Hahn, Asst. Extension Entomologist

An interesting caterpillar has been found apparently for the first time in Minnesota in several areas of the state. A genista broom moth caterpillar, Uresiphita reversalis, is about one inch long when fully grown. It's a pretty insect with a black head with white markings and a slender yellowish green or mustard colored body. There is a series of black and white colored tubercles (raised spots) running down its body with white hairs coming out of them.

When gardeners have discovered this insect in Minnesota, it has been feeding on false indigo, Baptisia. According to BugGuide this caterpillar has also been reported to feed on Acacia, Genista, Lupinus, Texas Mountain Laurel (Sophora secundiflora) and other pea family shrubs as well as Crapemyrtle (Lagerstroemia indica) and honeysuckle (Lonicera spp.).

The adult has a conspicuous snout and holds it wings in a delta shape when at rest. The forewings are light to medium brown with several small dark spots and marking while the hind wings are yellow or orange (see the Moth Photographers Group for images and the known distribution in the U.S.).

Genista broom moths are generally distributed throughout much of the southern U.S. It has been found as close to Minnesota as Iowa and Wisconsin (which are also seeing somewhat higher than normal numbers of this moth this summer). The appearance here of this insect is likely the result of migrant moths moving into Minnesota, possibly with the help of weather patterns. A perusal of the University of Minnesota's Insect Museum emphasizes that lack of genista broom moths found in Minnesota; only nine adult moths were found in the collection and none of them are from Minnesota.

We appear to be near the end of their feeding now as larvae look like they are getting ready to pupate. If you find these caterpillars in your garden and they are about one inch long, you can ignore them as they are essentially done with their feeding. If they are smaller, you have a few options. Probably the easiest thing you can do is to handpick them. It they are numerous, consider a low impact insecticide, such as insecticidal soap, spinosad, or Bacillus thuringiensis.

It is unclear whether genista broom moths will survive winters in Minnesota. If you have discovered this caterpillar in your garden, please contact the author (hahnx002@umn.edu) and report it. We are trying to establish where these insects have been discovered and whether they are found in the same sites next summer.

Jeffrey Hahn, Asst. Extension Entomologist

There have been many reports of cicada killers, Sphecius speciosus, nesting in yards, gardens, parks, and other areas. These wasps are large, 1 - 1 ½ inches long, with a black and reddish brown thorax, amber colored wings, reddish brown legs, and a black abdomen with yellow bands. They are found nesting in the soil where they prefer, well-drained, light soil exposed to full sun. A cicada killer is a solitary wasp, so you will only find one wasp per burrow. However, they are gregarious, meaning that you can find a number of them in a small area, sometimes establishing large aggregations of nests.

As their name suggests they catch cicadas. Cicadas are stout, winged insects common during the summer. However, people are more likely to hear them as they produce a power line like hum that is heard during the day. Once a cicada killer captures a cicada, she uses her stinger to paralyze it. She carries the cicada back to her nest where she will lay an egg on it. Once the grub-like larvae hatches, it feeds on the cicada. After it consumes the cicada, it pupates and remains in the burrow until next year.

Despite their size, cicada killers are not dangerous. While females have stingers, they are unaggressive and ignore people. They do not have an instinct to protect their nests (like yellowjackets and honey bees) and you can walk amongst them with little worry. Of course if you handle a cicada killer or it feels threaten, it can sting to protect itself.

Males on the other hand are territorial, looking to mate with females and chasing away other males. They can act aggressively if you enter an area they are patrolling. They will fly up to you, challenging you. Fortunately, it's all bluff as they lack a stinger and are harmless. Admittedly, that can be challenging to hold your ground when a large wasp is zooming around you but they can not hurt you.

Fortunately, cicada killers are just annoying. It is possible that their tunneling can undermine patio bricks but they are not going to be more of a problem than that. If you have property where cicada killer are nesting, there are couple of options to consider. The first is to ignore them and let them run their course. Remember, there is very little risk of stings and they will go away on their by the end of the summer. However, if they enjoyed nesting there this year, there is a good chance they will return next year.

Another option is to treat the nests. Keep in mind that generally broadcast spraying the areas where they are nesting is not very effective. Instead, apply an insecticide into each individual nest entrance. Dusts are most effective, although sprays can help reduce numbers. Effective active ingredients include permethrin and carbaryl. If you have trouble finding an appropriate insecticide, contact a lawn service to treat the cicada killers for you; they have access to turf products, like those containing fipronil or deltamethrin, that home residents can not find.

Karl Foord - Extension Educator, Horticulture

I was vacationing at Scenic State Park last month, and while driving down the road to Big Fork I saw a patch of common milkweed (Asclepias syriaca) along the roadside (Photo 1). I decided to stop and see if milkweed's reputation as a butterfly magnet was truly deserved.

I stood in the patch for an hour. It was like being in a natural butterfly house. The amount of activity was amazing. I would estimate there to have been at least 100 butterflies in this approximately 15' x 20' patch. There was also a dizzing array of butterfly species. I have attempted to record this diversity with photographs, and using Larry Weber's Butterflies of the North Woods, have identified 26 different species.

I will divide the findings into three articles; brushfoots, skippers, and a collection of sulphurs, coppers, hairstreaks, and day-flying moths.

Karl Foord - Extension Educator, Horticulture

This is a continuation of the butterflies encountered in a roadside milkweed patch.

Karl Foord - Extension Educator, Horticulture

This is a continuation of the butterflies encountered in a roadside milkweed patch.

In conclusion, I would have to say that milkweed certainly lives up to its reputation as a butterfly magnet. I am looking for a place to establish a milkweed patch and invite the butterflies.

Jeffrey Hahn, Asst. Extension Entomologist

Deer flies (family Tabanidae) have been particularly bothersome in many areas of Minnesota this year. These flies are about 1/4 - 3/8 inch long and are stout-bodied. They have yellow or black colored bodies with dark colored markings on their wings.

The larvae live in aquatic or semiaquatic areas, like marshy areas, streams and ponds. Adults are found near these breeding grounds, especially along the edge of woodlands but they are strong fliers and can be found miles away from these breeding areas. Watch out for deer flies especially on sunny, calm days. They have a tendency to wait in shady areas for hosts and ambush them as they move past. Deer flies primarily use sight to find a host and seem to be particularly attracted to moving, dark shapes.

They go for the head and neck when biting people. They inflict a painful bite as they use knife-like mouthparts to slice a wound in the skin and feed on the resulting blood. Fortunately, deer flies do not vector disease in Minnesota, although some people can suffer allergic reactions to the bites. In addition to humans, these biting flies also attack many different animals, including deer, horses, and cattle. Deer flies are most common in June and July, although can persist throughout the summer.

Unfortunately, we have very limited options when it comes to preventing deer flies from biting us. It is not practical to control immature deer flies by eliminating breeding sites, i.e. marshes, streams, and ponds. There are just too many potential sites to treat and the risk of environmental harm is too great. It is also prohibitive and impractical to treat adult flies in yards, parks and others areas with insecticide applications.

Control of deer flies usually boils down to personal protection, i.e. protective clothing, such as hats, long-sleeved shirts, and long pants to help protect exposed skin. You can also try a mosquito repellent, i.e. DEET and permethrin (follow all label directions), although the results are inconsistent.

There are also a variety of devices that purport to protect people from deer flies. One method involves placing sticky patches on the back of hats. In theory deer flies land and stick to the patch before they can bite you. Another device is the trolling deer fly trap. You use a blue cup covered with glue. You mount it either to hats or caps or machinery, such as lawn mowers.The idea is the deer flies are attracted to the cup, land and get stuck on the glue, preventing them from biting you. It is advertised to be most effective when it is moving.

Karl Foord - Extension Educator, Horticulture

In the article Swamp Milkweed - Great for Nectar - Bizarre Flowers that appeared in the June 15 Issue of Yard and Garden News, I lamented the fact that I had no pictures of insects carrying the pollinia of milkweed.

Although the pictures in this article are of insects on common milkweed (Asclepias syracia) and not Swamp Milkweed (Asclepias incarnata) the flowers are similar enough to be applicable.

Please note the pollinia on both a native bee and a fritillary butterfly.

Jeffrey Hahn, Asst. Extension Entomologist

A large flight of variegated cutworm moths moved through Minnesota as well as Wisconsin this spring. This was particularly noticeable when clusters of eggs were found on many buildings and other structures during May (see June 1, 2012 Yard and Garden News)

The result of this activity is now being felt in home gardens as many different herbaceous plants that are being damaged by their feeding. Unlike subterranean cutworms that many gardeners are familiar with, variegated cutworms are a type of climbing cutworm that will feed on the foliage of plants. They typically chew irregular holes between the veins on the leaves. They have also been known to bore into flower buds. Be careful not to confuse variegated cutworm feeding with slug damage which can look similar. Slug feeding usually results in more ragged, irregular holes but to be sure, you may have to catch the culprits in the act.

Variegated caterpillars are generally dark-colored, ranging from brownish to black. There are four to five yellowish diamond-shaped spots on the top of the body starting at the head. They may also have a dark-colored 'W' on top of its body near the posterior. Like other cutworms, variegated cutworms curl into a ball when they are disturbed. These cutworms are large when mature, growing to 1½ to two inches long.

The biology of variegated cutworms in Minnesota is not clearly understood. They apparently can overwinter in Minnesota either as pupae or larvae. However, most of them are probably carried up on the jet stream as adult moths and deposited into Minnesota during spring. They are reported to have two generations in the northern U.S. so we can expect to see them throughout the summer.

If you are experiencing problems with variegated cutworms, you have several options for managing them. You can try handpicking them. You might even be able to put out boards and trap some. If the problem is severe enough, you may resort to insecticides. Spinosad is a good option if you are looking for a low impact product. There are also a variety of residual insecticides to choose from, including permethrin, bifenthrin, cyfluthirn, and carbaryl.

A question that gardeners in northern Minnesota are asking is whether they will now start seeing this insect every year when they rarely or never saw it before. The good news is that the odds are in northern Minnesota's favor for not witnessing a repeat performance by variegated cutworms next year. We would have to experience the same perfect storm of weather conditions that allowed such a large number to migrate up to northern Minnesota and that is not likely.

Jeffrey Hahn, Asst. Extension Entomologist

Now is a good time to take a close look for wasp nests around your home. They are getting large enough to be noticed but have not reached their peak size yet. Wasps can nest in a variety of locations. Some species commonly nest under eaves of homes, the branches of trees and shrubs, and similar open, exposed areas. They also commonly nest in the ground, especially in old rodent burrows, as well as wall voids, attics, and other hidden sites. If you see any kind of persistent activity of wasps in a particular location, take a closer look to see if there is a nest involved.

One wasp, the European paper wasp, is interesting because of its ability to construct small nests in many different, unusual sites. Just in the author's backyard, they have been found nesting in the tail pipe of a unused van and inside an unused bird feeder. Paper wasps typically nest on the underside of horizontal surfaces. However, European paper wasps have the ability to construct their nests at angles. This wasp is also somewhat unique because while other wasps do not reuse their nests, they frequently reuse them which can result in larger than normal sized nests (for a paper wasp).

If you do find a wasp nest, the particular control you use will depend on factors, such as where the nest is located, how close to human activity it is, and whether the nest is out in the open or hidden. Click here for more specific information on controlling wasp nests.

Jeffrey Hahn, Asst. Extension Entomologist

This June has seen a lot of activity by leafcurl ash aphids, a type of woolly aphid, not only in the Twin Cities but also in a number of other areas in Greater Minnesota. Like other aphids, leafcurl ash aphids use piercing - sucking mouthparts to feed on the sap in the leaves. This feeding causes leaves to become tightly curled, puckered, and distorted. To verify leafcurl ash aphids, unroll the leaves. The aphids are a light green and no more than 1/8 inch long. They produce a conspicuous white waxy material that covers the aphids as well as the leaves.

These aphids also produce a lot of honeydew. Honeydew is a sticky waste material because the aphids are not able to digest all of the sugars in the sap. Any objects under a leafcurl ash aphid infested tree can get coated with this substance. Later you might find sooty mold, a black fungus developing on the honeydew. Fortunately, light infestations of sooty mold causes little damage to plants.

These aphids were even reported as nuisances when they would fall down on people in their yards (which is not conducive for graduation parties and other outdoor activities).

Leafcurl aphids feed on the new growth that expanded this spring. Colonies last until mid-summer. Winged forms are produced which migrate to the roots of ash where they remain for the rest of the year. Leafcurl ash aphids have always been in Minnesota but have been infrequently noticed or reported over the last 5 - 10 years.

Although the damaged leaves are conspicuous, when you look closely, just a small number of leaves within a tree are actually affected by leafcurl ash aphids. Even the leaves that are distorted can still photosynthesize so there is very little risk to the health of ash.

While insecticides, such as imidacloprid and dinotefuran are effective against these aphids, they are rarely warranted to protect trees and are not suggested. Even if you kill the aphids, the distorted leaves will remain for the rest of the season. While this can affect the trees' appearance that is of small consequence compared to other problems, especially the risk of emerald ash borer. 

Karl Foord - Extension Educator, Horticulture

I was walking through the Horticulture Display Garden at the University of Minnesota St. Paul Campus. A bee landed on the ground and disappeared. I got my camera but couldn't find the hole it had disappeared into, so I waited. In a few minutes the bee returned with a bit of leaf rolled under its abdomen and again disappeared down the now somewhat visible hole.

This was no leasurely entrance and exit from the hole. The time from seeing the bee approach the hole to disappearance was less than one second. It took less time for the bee to show at the top of the hole and exit. The bee exited headfirst so it had had enough room in the hole to turn around.

The bees that nest in this way are aptly named Leafcutter bees and are in the genus Megachile (Photo 1).

They are identified by the hair on the bottom of their abdomen which traps pollen. They do not have a pollen basket like honeybees.

Photo 2 shows a leafcutter bee next to a honeybee to show the size difference.

I documented this event with a video:

Leaf-cutter bee building nest

The bee took between 45 and 60 seconds to leave the nest retrieve a leaf piece and return to the nest. Entry and exit events have been patched together and slowed down by 50%.

Sometimes even at half speed the bee moves too quickly to appreciate what is happening, so I made a collage of still photos of nest entry (Photo 3) and nest exit (Photo 4).

I also wanted to know where it was getting its nest material. I found that leaves of Long leafed Speedwell Veronica longifolia had the characteristic holes created by the leaf cutter (Photo 4). Note that not all the leaf cuts are the same; oval pieces are used to coat the sides of the nest, and circular pieces close up the nest cells.

Other leafcutter nest sites are created in gaps between stones or bark, hollow plant stems or other preexisting holes. These bees do no real harm to plants in collecting leaf material, and they are good pollinators. Keep an eye out for them in your garden. They are a treat to watch.

Jeffrey Hahn, Asst. Extension Entomologist

Hawthorn mealybug, Phenacoccus dearnessi, has been found infesting several hawthorns in Minneapolis. This insect is globular and red, although it will appear to be white as it is covered with a white waxy material. In addition to hawthorn, it can also attack mountain ash (an infested mountain ash was found adjacent to the hawthorns), cotoneaster, juneberry (amelanchier), and other plants in the rose family.

This is not a common insect in Minnesota. In fact in Minnesota the best place to find mealybugs is on greenhouse and house plants and not landscapes. Even our neighbors in Wisconsin and Iowa have not seen the hawthorn mealybug (so far). It is, however, found in northeast Illinois.

This insect colonizes the bark of twigs and small branches using its piercing sucking mouthparts to feed on the sap. Hawthorn mealybugs also produce a lot of honeydew, a sugary waste material as a result of feeding on the sap. Honeydew is shiny, clear or whitish in appearance and sticky. Honeydew can also lead to sooty mold, a black fungus that colonizes the honeydew. Hawthorn mealybug has the potential to weaken branches and cause dieback, although that has not been noticed on infested trees here so far.

Hawthorn mealybugs appear to have one generation per year. They mature in the late spring. Eggs hatch and nymphs are active by early summer. After feeding on leaves briefly, the nymphs move to twigs and feed in protected sites.

Because of the white waxy material that is present and the habit of the nymphs to feed in protected places, direct insecticide control can be challenging. However, if management is necessary, an application of a systemic insecticide, like imidacloprid and dinotefuran should be effective.

Jeffrey Hahn, Asst. Extension Entomologist

Some people have discovered the sudden appearance of medium sized flies in their homes. Blow flies are iridescent green, blue, or coppery colored flies while flesh flies have dark colored bodies with three black stripes on their thorax and a checkerboard pattern on their abdomen. Both types of flies lay their eggs on dead animals and decaying garbage. The larvae are smooth, cream-colored, legless maggots that are carrot-shaped with the narrowest end by the head. When fully grown, they are about 3/4 inch long.

When a dead animal becomes trapped inside a home, e.g. inside a ceiling or wall void, and dies, it is not uncommon for it to attract these flies which lay eggs on the corpse. Eventually they turn into adult flies which can emerge into the home. It is also possible to see the maggots inside a home. As mature maggots wander away from their food source to less crowded sites to pupate, they can inadvertently move through light fixtures or other spaces and fall into the living space of a home.

These flies are generally harmless to people and property, although because of their unsanitary habits they do have the potential to spread filth-related diseases such as diarrhea and dysentery. On the plus side, they are helping us out by removing and recycling organic material.

A blow fly or flesh fly infestation will persist until the carcass is consumed. The most effective method to control them is to remove the food source, i.e. the dead animal. Unfortunately, this is usually not practical as the animal is typically trapped in an inaccessible place. Be patient and eventually the dead animal will be removed naturally by the maggots. The flies and the maggots will go away on their own once the food source is consumed. This generally takes several weeks to happen.

Click here for more information on summer flies.

Jeffrey Hahn, Asst. Extension Entomologist

During June, some people encountered eyed click beetles, Alaus oculatus, an interesting and conspicuous looking insect. An eyed click beetle is large, about 1 - 1 3/4 inch long. The wing covers are black mottled with small whitish patches. What are immediately noticeable are the two eyespots on its prothorax (the area behind its head) which are velvety black surrounded by a whitish ring. Eyed click beetles are associated with decaying logs and stumps and are found in open wooded areas. Watch for and enjoy the adults during spring. This insect is harmless and just a curiosity.

Jeffrey Hahn, Asst. Extension Entomologist

The moment many people have been dreading has arrived - Japanese beetle (JB) are starting emerge. It is not necessary to panic as they are not out in force yet. There have been a few individuals that have been found early (normally JB is not out until the first week of July). However, you know the rest are not too far behind. In fact with the recent rains, we could be seeing large numbers will probably emerge within a week or less.

JB is a pest because the adults feed on the leaves and flowers of many plants while the grubs feed on the roots of turf grass. If you have seen JB grub damage in the past, July is a good time to treat your yard. Use a preventative insecticide, like imidacloprid, after you see adults flying, about late June or early July this year. By the time eggs are laid and grubs hatch, about two to three weeks, the insecticide will be taken up by the grass and the young grubs will be exposed to it.

As the grubs get older they are less affected by preventative insecticides. It is still possible to control them with a curative insecticide, such as trichlorfon (e.g. Dylox). You can effectively treat JB with a curative insecticide until about mid-August. Remember to only treat the grubs if you are experiencing problems in your lawn. It is not effective to treat grubs to reduce the number of adults that are seen in your garden. Adult beetles are good fliers and can easily fly into your yard from the surround neighborhood.

You have a variety of options for managing the adults, including handpicking, low impact products like Neem and pyrethrins containing PBO, and residual insecticides, like permethrin and carbaryl (Sevin).

Another option is the use of a systemic insecticide, like imidacloprid (various trade names) and dinotefuran (Safari). They are easy to apply and are long lasting. They do not kill JB quickly but they do cause them to stop feeding with death coming later. One important drawback of these products is they are very toxic to bees. Avoid treating plants, like linden and roses, that are very attractive to bees. It doesn't matter that the trees and shrubs are not flowering at the time of application as these insecticides will be active for a year. Another important consideration is that it takes some time, especially for imidacloprid, for the tree to translocate the insecticide (3- 4 weeks for large trees). If you have plants that have been plagued by JB in the past, now would be a good time to treat them with a systemic so the insecticide can protect them before much damage is inflicted.

For more information see Japanese beetle management in Minnesota.

Karl Foord - Extension Educator, Horticulture

Swamp Milkweed (Asclepias incarnata) as you know is an important plant for Monarch Butterflies. The plant also produces significant amounts of nectar and thus attracts a host of other pollinators including various bees and ants (Photo 1).

On close examination the flower structure is bizarre. Typical corollas face backward (Photo 1), whereas prominent coronas fold to form a tube of sorts out of which a horn projects toward the center of the flower. The stamens have fused to form a cylinder around the pistil with a pink stigmatic surface in the center (Photo 2).

Pollen has fused to form wings called pollinia which are connected by a dark pollinarium gland, the whole structure being called a pollinarium. You can see the wings protruding from the side of the fused staminal column (Photo 2). The strategy is for an insect to visit the plant looking for nectar and catch its leg on one of the pollinia wings which detaches from the plant and attaches to the insects leg. The insect carries the pollinarium to another flower where the horn may help in detachment placing pollen on the stigmatic surface.

I took many pictures hoping to find an insect with a pollinarium attached to its leg. Alas I did not find one. However, I did find pollinarium that had been transferred from another flower. They can be seen in Photo 3 where the top center section has three pollinarium and the top left section has two pollinarium where originally each had only one.

Jeffrey Hahn, Asst. Extension Entomologist

A large wasp has been noticed in the landscape recently. This insect is a type of ichneumonid (ich-new-MON-id) wasp known as Megarhyssa (meg-a-RISS-uh). Megarhyssa is a reddish brown and yellow insect (another species is black with an orangish head) with a body length of about one and half inches long. That does not include it ovipositor which is another two to three inches long (that's up to over four inches total length!). In addition to the ovipositor, you will find two sheaths protecting it which sometimes gives the appearance that it has three 'tails'. Sometimes Megarhyssa is confused for other large sized insects, e.g. mayflies or dragonflies, so look closely to be sure it correctly identified.

Ichneumonid wasps are parasitic upon other insects. Megarhyssa is a parasite of horntails. Horntails attack dying or recently dead hardwoods, such as oak, maple, birch, and elm. With her long ovipositor, Megarhyssa can drill 1/2 inch or more into the wood to deliver an egg into the horntail larva. When people see this ichneumonid wasp ovipositing into a tree, they believe that it is attacking it. Of course, this is not true. Once the egg hatches, the Megarhyssa larva slowly feeds on the horntail, eventually killing it. After it matures into an adult wasp, it emerges from the tree.

Despite her large size and her menacing ovipositor, ichneumonid wasps, like Megarhyssa, pose no threat to people. They are not aggressive and avoid us when possible. It is possible that if someone handled a Megarhyssa, she could try to jab you with her ovipositor if she felt threatened but she could only inflict a minor wound at best.

If you see Megarhyssa, just ignore her. Any that you find will go away on their own in a short time. It is never necessary to treat them with an insecticide.

Jeffrey Hahn, Asst. Extension Entomologist

Earwigs season is beginning as immature nymphs are starting to turn into adults. They are pests when they enter homes, often in large numbers, and become bothersome. They can also damage flowers and other plants in your garden. Earwigs can be challenging to control, especially when they are abundant. Here are some steps you can take to minimize them on your property.

Regardless of whether you are dealing with them in your home or garden, you can reduce their number by using traps in the landscape. Use rolled up newspapers cardboard tubes, or similar objects and set them up outside where you are see earwigs. They will crawl inside these objects by early morning in order to hide. You can then shake them into a pail of soapy water to dispose of them.

Moisture management is also important. Minimize excess moisture by keeping irrigation equipment in good working order. If you need to irrigate your garden, water less frequently but more deeply so the soil remains more dry, making it less conducive for earwigs.

If you are having a problem with earwigs in your garden, you can supplement your non-chemical efforts with an insecticide. You can treat the mulch with insecticide, e.g. lambda cyhalothrin, or put out chemical baits, e.g. carbaryl, around the affected plants. You can also treat affected plants directly with any one of a variety of garden insecticides, e.g. permethrin.

If you are having a problem with earwigs coming into your home, check around the outside of your home and seal or repair any openings or gaps you find that allows earwigs to get inside. Check particularly around the foundation, windows and doors. Also examine where siding and foundation meet as well as the areas around water facets and vents. You can supplement this with an insecticide application around the exterior the home, e.g. permethrin or cyfluthrin.

Jeffrey Hahn, Asst. Extension Entomologist

There has been a variety of curiosity questions received recently about interesting moths. Several people have reported seeing hummingbird moths (also called hummingbird clearwing), Hemaris thysbe and/or bumble bee moths (also called snowberry clearwings), H. diffinis, in their gardens. These moths, a type of sphinx moth, are daytime flyers. They have relatively small, stout bodies and their wings are mostly clear, lacking scales on them. They fly like hummingbirds, deftly hovering and flying around flowers as they visit blossoms for nectar. 

You can distinguish between them as hummingbird moths are little larger with a wingspan of about two inches. They have a yellowish body and the borders and veins of the wings are reddish brown. Bumble bee moths are a little smaller with an average wingspan of about 1 ½ inches. They have a yellow and black body with black veins and a narrow black band on the edge of the wings.

Another sphinx moth that has been noticed lately is the whitelined sphinx moth. It is a large moth with a wingspan between 2 and 3 ½ inches. The first pair of wings are dark colored with a large white stripe running from the wingtip diagonally to the base of the wing and six smaller white lines crossing it. The second pair of wings is dark with a pinkish band. This moth is active at dusk as well as at night. It also flies around flowers like a hummingbird.

Later their larvae may be found in gardens feeding on evening primrose, grape, plants in the Rosaceae (rose family), and other herbs and woody plants. This caterpillar grows to be as large as three inches long with a distinctive horn on the end of its body. Most are green with black stripes and yellow and orange markings, although some are mostly black with some greenish yellow. 

Two giant silkworm moths may be seen now. Both species overwintered as cocoons and started to emerge during late spring. The cecropia moth is reddish brown with a wingspan of five to six inches. The polyphemus moth is a brown moth with a large blue and yellow eyespot on each hind wing. They will produce caterpillars that will become large and conspicuous by late summer and early fall as they feed on the leaves of a variety of hardwood trees.

The cecropia caterpillar grows up to 4 inches long. It is light green with a double row of reddish orange knobs (turbercles) on the thorax behind its head. There are also series of smaller yellow and blue knobs (turbercles) on the abdomen. The

polyphemus caterpillar grows to be about 3 1/2 inches long when fully grown. It is a pale green with sparse long hairs along the top and sides of the abdomen. 

Jeffrey Hahn, Asst. Extension Entomologist

If you are thinking about treating forest tent caterpillars, check their size because the odds are it is too late to treat them any more this year. If they are between 1 3/4 - 2 inches long, they are either finishing or are done with their feeding. Forest tent caterpillars, sometimes called (incorrectly) armyworms have been active since mid to late April and typically feed 5 - 6 weeks. The best time to treat them is when they are half full grown size, or about one inch long.

Older larvae can cause problems by coming down from trees and wandering around looking for food. Sometimes they can severely damage nearby plants, including those in gardens. Other times, they are annoying when they crawl onto homes, sidewalks, decks, patios, outdoor furniture, and other objects. They may even pupate on homes and other things, further being nuisances.

They are difficult to deal with, especially when they are abundant. You can try to create a barrier with an insecticide, such as permethrin (be sure any insecticide you use is labeled for the area or plants you intend to treat). Otherwise use physical removal (avoid crushing the caterpillars if possible when they are homes). It is likely you will need to be persistent as effective physical removal is often time consuming. 

Click here for more information on forest tent caterpillars.

Jeffrey Hahn, Asst. Extension Entomologist

Many parts of Minnesota experienced large numbers of adult cutworm moths recently. However, it was not so much the moths that were noticed as were the many eggs that were laid on homes on windows, siding, soffits and other places. Clusters of eggs were reported from the Twin Cities up to northern Minnesota, especially in the northeastern part of the state. Some towns found that essentially all buildings had at least some eggs on them. One resident said he found as many 15 clusters of eggs on his home. Wisconsin also experienced a similar phenomenon with cutworm eggs found in much of the northern half of their state.

Insect eggs are often challenging to identify, especially to species. While it was fairly easy to diagnose the eggs as belonging to a moth, it wasn't until someone was finally able to catch the culprit in the act of laying eggs that the species could be identified as a variegated cutworm. Variegated cutworms are native to Minnesota but it is very unusual to see such large numbers, especially in northern Minnesota where they are rarely seen.

An individual variegated cutworm egg is tiny, about 1/50th in diameter. It is hemispherical with many ridges and is whitish or yellowish at first, before turning brown. There can be hundreds of eggs in a single cluster. Once they hatch, they are small and dark. As they grow larger, they are brownish to black with four to five yellowish diamond-shaped spots on the top of the body starting at the head. You may also see a dark-colored 'W' on top of its body near the posterior. They can be up to two inches long when fully grown.

You might expect that with so many eggs being laid that this would mean an increased problem with cutworms in gardens and agricultural fields. So far this has not been the case. Still, if you noticed clusters of eggs in your area, monitor your garden and watch for signs of cutworms, i.e. young plants cut off at ground level. The eggs laid on homes are little risk to gardens, as the caterpillars are very likely to die before they can move and find susceptible plants.  Click here for more information on cutworms, including management.

Jeffrey Hahn, Asst. Extension Entomologist

Insects are out in full force in gardens and yards this spring. Are any of these pests at your home?

Aphids are small pear-shaped, soft-bodied insects. They have been reported on roses and red elderberry this spring so far, but will feed on a wide variety of herbaceous and woody plants.

They feed on plant sap with a long, needle-like mouthparts. Plants typically do not exhibit noticable symptoms when infested by small to moderate numbers of aphids, although large numbers can cause wilting and loss of plant health. There are many natural enemies to help keep aphids under control, especially ladybird beetles. If you are dealing with larger numbers of aphids, try spraying them off with a hard stream of water.
If you need a low impact insecticide, consider insecticidal soap or horticultural oil.

Fourlined plant bugs have just started to hatch.

They feed on a wide variety of herbaceous plants as well as shrubs and fruit. Look for reddish nymphys now (Photo 1);

eventually they mature into greenish yellow insects with four black stripes. When fourlined plant bugs feed, they produce small, round sunken lesions on the leaves. Large numbers can reduce plant health, although in many cases only smaller numbers are present which cause cosmetic damage.

When practical, crush nymphs that your find; you can also spray them with insecticidal soap. You will need a residual insecticide for the adults.

See also, http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/e121plantbugs-forulined.html

There have been several species of sawflies reported recently.

European pine sawfly feeds on the old needles of pine especially mugo pine.

Columbine sawfly feeds on the edge of the leaves of columbine, sometimes feeding until there is nothing left but the midrib.

Roseslug causes a different type of damage on roses. They feed on one layer of leaf tissue, feeding between the veins. At first, this damage looks kind of lacey, as if something sucked the green out of the leaves, Later these damaged areas turn brown.

Sawflies are no more than 1 inch long when fully grown (foseslugs are just 1/2 inch long), so look carefully for them on your plants.

Once your find them, you can use insecticidal soap, horticultural oil, spinosad or a residual insecticide.

Jeffrey Hahn, Asst. Extension Entomologist

Did you have a problem with forest tent caterpillars (FTC) last year? If you did, expect to see them again soon as they have started to hatch during late April. You can recognize these caterpillars from their blue and black body and white footprint or keyhole shaped spots on their back. Despite their name, FTC do not construct conspicuous webs. If you find a large tent in a tree this spring, that is from eastern tent caterpillars.

FTC are primarily a problem because they feed on the leaves of trees and shrubs, especially aspen, birch, oak, and linden/basswood. If they are abundant and their normal food is in short supply they will crawl down trees and also feed on fruits, vegetables, and flowers. They can also become nuisances when they wander around looking for sites to pupate (which has earned them the nickname 'armyworms'). This can lead them to crawl onto nearby buildings and other structures.

Populations of FTC are cyclical, with periods of few and increasing numbers of FTC lasting about 8 - 13 years. Eventually these increasing numbers hit outbreak numbers which lasts about three to four years. FTC populations in the Twin Cities, though, appear to be less cyclical.

Fortunately, healthy, mature trees can tolerate severe defoliation, even in several consecutive years. Young and unhealthy trees are more susceptible to injury and should be monitored closely for the potential need to treat. There are a variety of residual insecticides that you can use if you want to protect your plants. Consider using products that have a low impact on the environment, such as Bacillus thuringiensis, spinosad, and insecticidal soap. Bacillus thuringiensis is a particularly good product if the tree is flowering since it will not harm visiting honey bees.

There are also insecticides available to protect garden plants, including food crops. Be sure to check the label to be sure the particular product you want to use is cleared to treat the plants you wish to protect.

Jeffrey Hahn, Asst. Extension Entomologist

Some people have been experiencing clover mites around their homes recently. Identification is important as they could be misidentified as other types of mites or even very small ticks. Clover mites are about the size of a pinhead (about 1/30th inch long) and are reddish or brownish in color. They have a round body and eight legs with the first pair of legs particularly long. People find them on the outside of their homes as well as around windows.

Clover mites feed on grass and clover during summer (they are not pests on these plants). They take shelter in and around buildings during the fall. You might see them then but they are much more commonly noticed during spring. They can potentially occur in very large numbers around buildings and have no problem getting inside, especially around windows, because of their small size. They love being in the sun and are most common on the south sides of homes. Fortunately, clover mites are not harmful to people or our property. However, they can stain surfaces if they are crushed.

If you are not seeing many, the best bet is physical removal. Use a vacuum cleaner or gently wipe them up with a damp cloth to help minimize crushing them. Clover mites are a temporary problem that will go away on its own when the weather become warmer.

If you having a problem with large numbers entering your home, you can treat the foundation to deter them with an insecticide containing bifenthrin (be sure it is labeled for spraying the outside of homes). You can also consider hiring a professional pest control service to treat your home's exterior.

If you deal with this problem most years and are looking for a more sustainable approach to managing them, you can try maintaining a barrier of clean, bare soil around your home, i.e. free of grass and leaves. Clover mites generally do not cross such a barrier. This barrier should be about 18 - 24 inches wide. If you do have annuals, perennials, or shrubs planted in this zone, have them far enough apart so the clover mites can not easily bridge across this barrier. Landscape rock apparently is not enough of a deterrent to keep clover mites away from buildings.

Karl Foord - Extension Educator, Horticulture

While exploring the Minnesota Landscape Arboretum I encountered Dr. Stan Hokanson the woody plant breeder in the Department of Horticulture Science. He introduced me to the Clove Currant (Ribes odoratum). The odoratum nomenclature is well deserved. Clove Currant give off a very pleasant spicy fragrance hinting of clove and alspice (Photos 1 and 2). The plant has yellow flowers and a corolla long enough to restrict its pollinators to those with long tongues like bumblebees (Photos 3 and 4).

Another tree with fragrant flowers is the Korean crabapple (Malus bacatta jackii) one of the earlier flowering crabapples. The flowers are being visited by native bees (Photos 5 and 6).

Jeffrey Hahn, Asst. Extension Entomologist

Throughout March, people have been having problems with nuisance insects in their homes, especially cluster flies, boxelder bugs, and (multicolored Asian) lady beetles.  Fortunately, these insects are harmless, although they can be annoying, especially when a lot of them are present.  Here are a few things to keep in mind when dealing with these insects.

First, it is important to know that these insects are not reproducing indoors.  Because they emerge from their hiding places periodically throughout the winter and early spring, it appears they are laying eggs and their offspring are emerging.  In fact, all of the insects you see now entered your home last fall.  They hibernate in balls or clusters in wall voids, attics, and similar areas.  As the temperatures warm, the insects in the outer layers become active first and then emerge into the living quarters of the home, explaining why they do not all become active at the same time.

Because they are emerging from hidden sites, it is not practical to treat them to prevent their emergence.  Once they are out in the open, your best bet is physical removal, such as vacuuming.  Eventually, all of these overwintering insects will become active and move away from their overwintering sites.  Fortunately for those trapped in homes, they are short lived

To minimize these kind of problems in the future, it is important to treat these insects in the fall as they are first trying to enter your home.  This is a two pronged approach.  First it is important to inspect the outside of the home during summer and seal spaces and gaps that may be used by these insect to get inside.  This should be followed up with an insecticide application in the fall, just as these insects are trying to get inside.  It is not possible to prevent all nuisance insects from entering into a home, but you can reduce the number that do causing fewer problems later during the winter and spring.  You can find more information here on cluster flies, boxelder bugs, and lady beetles.

Jeffrey Hahn, Asst. Extension Entomologist

There have been a lot of questions concerning Japanese beetles (JB) as we go into the 2012 growing season.  JB has been increasing in numbers over the last four or five years, especially in the Twin Cities area, although JB are also starting to be found more commonly in other areas of the state as well.  They can be challenging to control and people will take any steps they can to reduce their numbers in their gardens and yards.

The first question people ask is how bad are JB going to be this year.  There isn't an easy answer to that question and it undoubtedly will vary according to where you live.  If JB was abundant last year, there is a good chance they will be common again this summer.  However, a factor that can have an impact on JB numbers is soil moisture.   The eggs and the young grubs have a harder time surviving in dry soil so if dry conditions exist when JB are laying eggs, that can reduce the numbers of adults that are seen the following year.  Of course, if the turf area is well watered, that will make it easier for JB to survive.

It is difficult to determine what role the winter weather had on JB populations.  Although the mild temperatures favored JB, the lack of snow cover could have been potentially detrimental to them.  The early spring we have been experiencing should not have any effect on JB numbers.  However, expect them to emerge earlier than normal.  In a typical season, JB emerge around the 4th of July.  If the weather holds, the adults could be active as soon as the 3rd or 4th week of June.

And speaking of the early spring, people are wondering whether they can still treat JB grubs this spring or whether it is too late.  An important to factor to first consider is whether your primary goal is to control the grubs, because you are seeing damage in your turf, or the adults because of damage they have done to garden and landscape plants.  If your aim is to reduce the adults by controlling the grubs, you can save yourself the effort as this is not effective.  The adults are mobile and can easily fly in from areas outside your property. 

If you are finding turf damage due to JB grubs, and if you have had a lot of adults on your property look carefully for this, then the best time to treat for grubs is in July.  If you are going to use a preventative, such as imidacloprid (e.g. Merit), then you should be treating your turf when you first see the adults flying.  About two to three weeks after the first adults have emerged, JB eggs are hatching.  Preventative insecticides are most effective against the first instar larvae but not the older second and third instar larvae so the timing is critical. 

If JB grubs are not treated then, it is still possible to control them with a curative insecticide, such as trichlorfon (e.g. Dylox).  You can effectively treat JB with a curative insecticide until about mid-August.  By spring, the grubs are too large to effectively treat them.

Jeffrey Hahn, Extension Professor and Asst. Extension Entomologist

There have been a number of reports this winter of caterpillars active on top of the snow. This mystery caterpillar is an exotic moth known as Noctua pronuba, commonly called the winter cutworm or (large) yellow underwing. The first report this season came from Itasca county in December. Then on New Years day, after we had a light snowfall, there were several reports of this insect in Washington county in the eastern Twin Cities area (note: there were also a number of reports across the border in northeast Wisconsin). One person said they found about 30 of these caterpillars while another said they saw as many as 60 - 70 at a time.

There is a precedent to seeing insects outdoors during the winter. Insects, including snow flea, snow scorpionfly, and small winter stonefly, are know to tolerate colder temperatures and can be found on top of the snow during winter. Now we can add winter cutworm to this list.

This caterpillar overwinters as a large larva. It has a smooth, hairless body and can be as large as three inches when fully grown. It is colored light to dark brown with a series of black dashes running down its back. It also has two black bracket-like markings on its head. As an adult moth, it has brownish forewings and bright orangish yellow hind wings with a black band near the margin of the wing.

Originally from Europe, winter cutworms were first found in North America in Nova Scotia in 1979. They are now generally distributed throughout the northeastern U.S. They are also found in the upper Midwest as well as a variety of other states, even California. They were first noted in Minnesota sometime in the late 1990's from moths collected at black light traps in Lamberton (in Redwood county in southwest Minnesota). It is likely there were present in other counties at that time and they are probably now generally distributed throughout the state. Interestingly, this is the first time that these caterpillars have been reported during the winter.

This insect feeds on a wide variety of agricultural and garden plants. Despite the fact that winter cutworm has been in Minnesota for 12 - 14 years, it has not been reported as a problem in agricultural fields. It is possible for home gardeners to find this insect but it is generally not expected to be a significant problem. Look for them right away in the spring and then again during mid to late summer and into the fall. If you do find winter cutworms, just treat them like any other cutworm.

Jeffrey Hahn, Asst. Extension Entomologist

Many people are familiar with boxelder bugs, multicolored Asian lady beetles, cluster flies, and other nuisance insects that can be found in homes. But occasionally less familiar insects are found inside. On one such occasion, a homeowner reported finding a lot of wasps nesting in her home. In fact, she had identified them from the internet as Cerceris fumipennis.

This wasp species is a solitary wasp in the family Crabronidae. It has gained fame recently as a method for detecting emerald ash borers (EAB). This native ground nesting wasp hunts buprestid beetles, including EAB, which it paralyzes and carries back to its nest to feed its larvae. Location of a nest with captured EAB indicates the presence of EAB in the area. More information on Cerceris wasps can be found here.

This wasp's status is unclear in Minnesota and nests have not been discovered so far. Ultimately, you would not find this wasp indoors in the winter as they do not overwinter as adults.

A sample of insects was requested from the homeowner with the expectation being that paper wasp queens, Polistes spp., which overwinter gregariously in homes would be found. It was therefore quite a surprise to find that not only were the insects not paper wasps, but were instead flies. A run through the diagnostic keys identified them as soldier flies (family Stratiomyidae). These flies are typically black and yellow insects that can appear to be wasp- or bee-like.

A run up to the museum, and with the help of John Luhman, the soldier flies were identified specifically as Ptecticus trivittatus. This is a species that is particularly associated with composts. The conclusion was that these soldier flies most likely originated from a compost nearby in the neighborhood and they found their way to this home in which to overwinter. There had a mild stretch of weather when the homeowner first noticed the flies which would have been sufficient to cause overwintering insects to become active. There are other flies, such as cluster flies and face flies, that overwinter in structures so this made sense.

The homeowner kept insisting that these insects were nesting in her home. She was continuing to see consistent numbers of them; at one point she was seeing as many as 20 - 30 at a time. She eventually asked whether these flies could be associated with composts. They had brought a worm compost box indoors so the worms would not freeze. It was in a plastic tub with a cover but there were small air holes. She wondered whether the soldier flies could be in the compost. That of course was the source of the problem and why they were seeing such persistent numbers. The adult flies would be short-lived but to put an end to the problem it was important to erect some kind of screening so the flies could not escape.

A good example of how the identity and biology of an insect has a direct impact on its management.

Karl Foord, UMN Extension Educator

I often see recommendations to use the pesticide with the least impact when controlling pests. However, prior to spraying every effort should be made to avoid pest outbreaks by using the best management practices for a particular crop. For example, most fungi need a period of wetness for their spores to germinate. Managing systems to permit maximum airflow reduces drying time on leaves and reduces the opportunities for fungal spores to germinate.

For the purposes of this article let's assume that all best efforts were made and a spray as the last resort was required. How would you go about choosing the one with the least impact? The first question might be impact on whom, with the second being how one would measure such impact. At a University of California Davis website a series of pesticides is listed. Each pesticide is rated according to its impact on aquatic live, beneficial insects, honeybees, and humans. The human impact is separated into acute and long term impacts. Acute being what can happen to you today, and long term being what can happen over a number of years due to continued exposure at lower dosage rates.

Each chemical is given a potential hazard rating based on a series of other documents and warnings on the chemical's label. These are complicated but can be accessed at the website previously mentioned. The ratings range from no risk, no known risk, and very low risk to very high risk or no data available. For those pesticides labeled for strawberry, the impact information has been consolidated into a table where the materials have been ranked from lowest risk to those of highest risk (table 1). For example if you encountered slugs (mollusks) in your strawberries, the less impactful of the two active ingredients would be iron phosphate and not metaldehyde. So looking for a product with this as the active ingredient would be the first choice.

If you encountered tarnished plant bug in your strawberries, you would want to choose an insecticidal soap as a first choice over malathion. If you were forced to go to malathion you would realize that you would want to avoid any situation where the spray could get into surface water. You would also want to be particularly sensitive beneficial insects and honeybee pollinators and not spray when they are active, most likely after dark.

This table should permit you to select the least impactful chemical, and to apply it in a manner producing the least impact through an understanding what organisms were at risk from the application.

Jeffrey Hahn, Assistant Extension Entomologist

Not all small-sized flies that are found in homes are necessarily fruit flies. Another common type are moth flies, also called drain flies. These flies are about 1/8th inch long (or a little less) and are dark-colored with many hairs which gives them a fuzzy, moth-like appearance. They have leaf-shaped wings that are often held roof-like over their bodies (they are sometimes also held flat). If you look closely, you may be able to many parallel longitudinal veins in the wings.

Moth flies can be present anywhere in a home, especially in bathrooms, basements, and kitchens. These flies lay their eggs in moist, organic matter where the larvae, small, slender, legless insects, feed on decaying organic matter, fungi, algae, and similar material. They are commonly found associated with the gelatinous film found in sinks, shower and bathtub drains, and similar places. Moths flies can also be associated with sewage from sewer line breaks. Moth flies are primarily a nuisance because of their presence. They don't bite people but they can potentially be a mechanical vector of disease because of their association with filth.

The best control of moth flies is to remove the source of the infestation. You can not eliminate a problem by just spraying the adults that are out in the open, First check drains and basins for the presence of an infestation. If you are not sure, place some tape over the openings (sticky side down); flies will get stuck on the tape as they try to fly out. If you suspect a sewer line break under a floor or slab, it may be necessary to break through the floor or concrete to verify this.

If you are dealing with a drain, you need to remove the gelatinous gunk that has accumulated. You can do that by taking a brush with stiff bristles and physically removing it. Another effective option is to use biological drain cleaner which breaks down and removes he organic material. However the use of hot/boiling water, bleach, and chemical drain cleaners is not effective. Attempts to try to drown the larvae is difficult and is unlikely to be successful. If you are dealing with sewage from a broken pipe, it is critical to fix the break and remove the sewage and any contaminated soil that is present.

Karl Foord, UMN Extension Educator

Do you actually see things that you do not recognize? I was hunting for agates near Custer, South Dakota and went through a great agate field and picked a number of nice specimens. I then visited a rock shop and was introduced to the prairie agate which I had not seen in any of the rock books. I went back to the agate field and found quite a few prairie agates. I had been in that field earnestly searching for agates before and did not even see these types until pointed out at the rock shop. This begs the question, can you be looking right at something and not see it or rather not recognize it for what it is? It is not that your eyes did not see it but rather your brain was not ready to discern.
This brings me to the subject of beneficial insects in the garden. Have I not seen them because I did not know what I was looking for? As I look forward to next year's gardening, I want to put the idea of discovering more beneficials at the forefront of my mind. To aid the process I would like to be able to see what it is that I am looking for. As advanced responsible gardeners I think we have an obligation to recognize the dynamics at work in our gardens. To this end I offer the following challenge: how many beneficials will you be able to see and identify from your garden in 2012?

What follows is a gallery of 8 beneficial insects with pictures of their mature and immature stages. Also included is a table showing the types of insects on which they prey.

Please click here for the pdf of the gallery: Beneficials.pdf

Karl Foord, UMN Extension Educator

The goal of IPM is to prevent unacceptable levels of pest damage through the use of pest biology and environmental information. It seeks a solution that poses the least possible risk to people and the environment.

The great appeal of IPM is the understanding of the biological systems at play in the garden and the degree one needs to understand them in order to effectively use IPM strategies. This requires a certain knowledge and skill set. One needs to be able to identify the key insect and disease pests and the types of damage they inflict. One needs to understand the biology of these key pests and how climate influences their behavior. It is also important to understand the natural balances that exist in your garden ecology and to be able to identify beneficial organisms that are a part of that balance. The last item is to understand the use of various chemicals and their effects both direct and indirect. This is understandably quite a challenge. Among the many appealing aspects of gardening, one of them must be its challenges.

Most organisms living in your garden are benign in terms of our perspective of fruit or vegetable production. A few are labeled pests because they conflict with our goals, and a few are labeled beneficials because they tend to attack the pest organisms or because they aid in pollination and assure fruit set. Beneficial fungi and bacteria help plants absorb nutrients from the soil in the same way certain strains of E. coli help in the digestion of our food. However, consider the dilemma of labeling a yellow jacket that preys on caterpillars in the summer and feeds on ripe fruit in the fall.

IPM strategy begins with avoidance of the pest problem itself through use of pest-resistant varieties and cultural systems. For example, most fungi require leaf surfaces to be wet for a certain amount of time at a certain temperature for their spores to germinate. Cultural systems that reduce the opportunity for fungal populations to get established include: 1) proper selection of planting site, and 2) planting systems to reduce the time that leaf surfaces remain wet. Most fungal spores are omnipresent waiting for the right climatic conditions to grow, and by eliminating those microclimate conditions in our gardens we are using IPM strategies.

Some situations cannot be avoided by cultural systems and require monitoring of the plants by scouting for the presence of insects and disease. IPM recognizes that the garden exists within an ecosystem and as such there is a dynamic flux between predator and prey insect species, as well as a flux of fungal and bacterial presence based on temperature and moisture conditions.

The elimination of all insects through the use of a broad spectrum insecticide provides the opportunity for the fast reproducing prey species to bounce back and become an even bigger problem, or requires implementation of a time based spray schedule. The IPM strategy is to monitor insect levels and tolerate the presence of pest species as long as it remains below a threshold level. In commercial systems this threshold level is an economic level based on the cost of control materials and their application. For the home gardener this is probably not an economic number but rather an acceptable control point based on the expectations of harvest quality and quantity.

An insect example

Tarnished Plant Bug (Lygus lineolaris) is an insect whose nymph stage feeding can cause significant damage to strawberry fruit creating misshaped "button berry" fruit. In a commercial setting the nymphs would be sampled by walking through a field at 5% bloom and tapping blossom clusters against a white pan looking for the small green nymphs moving across the pan. If 25% of the 20 or more blooms tested have nymphs, the commercial action threshold has been reached and the grower should take action. This sampling would be conducted every few days to keep a close view of the pest situation.

For the home grower depending on the size of your planting, a pan of soapy water could be used instead of a white pan and all blossoms could be tapped with bugs falling into water and drowning. This would certainly reduce the population of tarnished plant bug and might reduce it below your threshold level. Also the plants could be examined for predators of the tarnished plant bug such as other true bugs "damsel bugs" or nabids (Family Nabidae), and big-eyed bugs (Geocorids), ladybird beetles, spiders, and parasitic wasps. Seethe following URL with descriptions of beneficial insects3: http://www.mda.state.mn.us/plants/pestmanagement/ipm/strawberry-guide.aspx
This would be an example of physical removal of the pest as opposed to chemical.

A Disease Example

The use of a fungicide is based on weather conditions and the fungus in question. Leather Rot (Phytophthora cactorum) is a fruit disease of strawberries that is best managed by judicious use of straw mulch. "Straw mulch can reduce fruit diseases better than fungicides."1 Both Gray Mold (Botrytis cinerea) and Anthracnose (Colletotrichum spp.) overwinter on strawberry leaf litter and spores are transferred to flowers by splashing dispersal in heavy rains. If the temperatures are optimal the spores will germinate. Gray mold is a problem when plants are flowering whereas Anthracnose is a problem when the plants are fruiting. The IPM approach to these diseases involves use of straw mulch to reduce splash effects, removal of leaf litter as a source of disease material mostly in the renovation process2, and use of fungicides if weather conditions are optimal for fungal development.

The more you look into IPM, the more the world seems to expand.

References:
Integrated Pest Management Manual for Minnesota Strawberry Fields Minnesota, Department of Agriculture, September, 2007.

Strawberries for the Home Garden

Field Guide for Identification of Pest Insects, Diseases, and Beneficial Organisms in Minnesota Strawberry Fields.

Further references

Managing Pests in Landscapes and Homes - A Homeowner's Guide to IPM in Minnesota

Jeffrey Hahn, Asst. Extension Entomologist

Fruit flies are particularly common in homes during fall. These flies, Drosophila spp., are about 1/8th inch long with a tannish body, and a dark-colored abdomen. An easy way to identify fruit flies is by their bright red eyes. However, their eyes do appear darker after they are dead and may not be as distinctive. Be careful, not every small-sized fly you encounter is automatically a fruit fly. Moth flies, phorid flies (also called humpbacked flies), and fungus gnats can also be common in homes. It is important to know which fly you are seeing because control will vary depending on which fly is present. If you have any doubts as to which fly is in your home, have an expert identify it for you.

Fruit flies can potentially be carried into homes in fruits and vegetables or they could fly in from the outside. Once in homes, they are attracted to fermenting and souring smells, e.g. around garbage containers and produce that is starting to become overripe. Fruit flies lay their eggs in a wide variety of sites as long as they are moist, contains fermenting organic matter, and are in reasonably undisturbed places.

You can help prevent fruit flies by eating fruits and vegetables while they are fresh or keep them refrigerated; do not allow produce to sit out and become overripe. Also, keep the inside of garbage containers clean from food residues. Rinse bottles and cans that you recycle and remove recyclables on a regular basis. Don't forget to periodically clean recycling containers to prevent a build-up of food residue. Remove garbage in tied plastic bags on a regular basis.

If you find you have a persistent problem with fruit flies, the most effective, permanent control is sanitation, i.e. eliminate their food source. Fruit flies are commonly found infesting overripe fruits and vegetables like bananas, tomatoes, potatoes, and onions. Also look for them around soft drink, wine, and beer bottles and cans that are being saved for recycling as well as in the recycling container itself. Another common site is trash containers especially when they are lined with plastic bags (look between the liner and the container). Remember that the source of the infestation may not be where the adult flies are found.

Fruit flies, however, will take advantage of a wide variety of different food sources and there are also plenty of unusual sites where you may discover fruit flies. You may need to be a detective and be imaginative to determine where they are coming from. In one case, fruit flies were infesting a tea maker after tea was brewed but was not cleaned out before it was put away. In another instance, they were found in rotting osage oranges (non-edible fruit that are purported to repel insects, spiders, and rodents) that were left out and forgotten. Remember that fruit flies are found in moist, undisturbed places where fermenting organic material is found.

Some people are tempted to spray fruit flies with an insecticide. While that will kill the flies you see, it is not a long term solution and more will return. Just spraying adults doesn't have any impact on the source of the infestation and the larvae that are developing. As long as a food source still exists, adults will continue to be present.

Fruit fly traps (either store bought or homemade) generally do not eliminate fruit flies. While you may capture some individuals, like spraying, it is difficult to catch them fast enough to actually eliminate them. However, you could use traps to help narrow down where infestations are located. By placing traps in every room, the trap with the most fruit flies usually indicates approximately where the problem can be found.

Jeffrey Hahn, Asst. Extension Entomologist

Fall webworm, Hyphantria cunea, is a web building moth that is common from mid to late summer.  It is yellowish or greenish with long, fine white hairs with two rows of black spots down its back, growing to about one inch long when fully grown.  However, an easier way to identify fall webworm is from the silken webbing that covers the ends of branches where the caterpillars feed in nonsocial groups.  These caterpillars feed on the leaves of over 100 different species of deciduous trees and shrubs, including black walnut, birch, ash, crab apple, elm, and maple.  

Fortunately, fall webworm normally has little impact on the health of large, vigorously growing, well-established trees (it is possible that small trees or shrubs can be completely defoliated in one season and could be injured).  Fall webworms are usually no worse than an eyesore because of the webs they construct, making management unnecessary.  This is especially during late summer as this feeding has little impact on plant health.  There are also natural enemies that help keep fall webworms in check and prevent serious outbreaks.  

If you want to try to improve the tree's appearance, you can try to pull the webbing and caterpillars off the branches (assuming you can reach them).  Although it may be difficult to remove the entire web, you may be able to damage it enough to eliminate the fall webworms.  You can prune out branches containing webs as along as removal is not excessive or the tree or shrub is left unsightly. Do not attempt to burn webs; this is more harmful to the tree than any control that is achieved.

If there are circumstances where it is necessary to treat fall webworms, they are vulnerable to insecticides if they are applied soon after the caterpillars start to construct their webs.  There are a variety of residual products that can be effective, including permethrin and bifenthrin.  If you wish to use a low impact product, try Bacillus thuringiensis, a bacterial insecticide.  It is specific to butterfly and moth caterpillars and has no impact on other insects as well as people and animals.  Once webs are larger, direct sprays do not penetrate through the webbing very well.  Another option is to use the dinotefuran, a type of systemic insecticide.  Another, systemic insecticide,  imidacloprid, however, is not very effective against caterpillars. 

Jeffrey Hahn, Asst. Extension Entomologist

Emerald ash borer (EAB) has been confirmed in two new locations by the Minnesota Dept. of Agriculture (MDA) on Friday August 26. One find was detected in the city of La Crescent in Houston county while the second was found in the Great River Bluffs State Park in Winona county, just eight miles apart. This is the first time EAB has been found in Winona county. Both discoveries were made when an EAB adult was found on sticky purple panel traps that were deployed by the MDA. No infested trees have been found to date, although surveys in those areas are ongoing.

For more information see the MDA news release. 

Late Breaking News:  On Wednesday August 31, MDA reported that EAB was found on another purple trap about 7 miles northwest of the positive trap location at Great River Bluffs State Park and about 7 miles east of Winona. 

Jeffrey Hahn, Asst. Extension Entomologist

There have been several reports of people seeing giant swallowtails, Papilio cresphontes, in the Twin Cities areas recently (they undoubtedly have been seen in other areas of Minnesota as well). This is noteworthy as these spectacular butterflies are not native to Minnesota but can occasionally be found during the summer as migrants from the south.

You can recognize a giant swallowtail because of its size, its wingspan ranges from 4" - 5 ½", and its black wings with yellow spots; the yellow spots on the forewings form an 'x'. Don't confuse it with a black swallowtail which also has black wings but is smaller, its wingspan is as large as 3 ½" and the yellow spots on its forewings are parallel and do not cross. Giant swallowtails can not reproduce in Minnesota as they need citrus trees and related plants for food for the larvae.

Jeffrey Hahn, Asst. Extension Entomologist

This is a common time of the year for wasp (primarily yellowjacket) nests to become conspicuous and more noticeable by homeowners. These nests have been present all summer but were small enough that they were not noticed then. Although this year would be considered to be no more than an average year for wasps primarily due to the late spring we experienced, if you have a wasp nest present on your property they are still a potential problem. What you decide to do with a nest can depend on a number of factors, such as how close to human traffic the nest is, is the nest is exposed or not, and how close to a hard frost we are.

For more information, see the following article on wasps (yellowjackets),

Jeffrey Hahn, Asst. Extension Entomologist

Q. Where did JB come from?

A. The first JB was found in Minnesota in 1968 after which the Minnesota Dept. of Agriculture (MDA) started a trapping program. Despite traps being set up in the Twin Cites area, between 1969 - 1979, only three beetles were captured. Between 1980 - 1983, only 16 JB were found. There were no trapping between 1984 - 1991.

The trapping program resumed in 1991 and in 1992 298 JB were trapped. In 1994, over 6,800 were trapped in 12 counties. In1999, nearly 36,000 were trapped; over a half million in 2000; and over 1 million JB trapped in 15 counties in 2001 (99% of these were found in Hennepin and Washington counties). Then in 2002, the numbers crashed and only 1,682 in 19 counties were found.

MDA discontinued their trapping program after that, feeling that JB was established. Very few reports were received by Extension over the next several years. Starting in 2005, Extension started receiving noticeably more calls and e-mails on JB. Each year afterwards contacts about JB gradually increased and as they become more common each year. As of 2009, JB had been found in 27 counties, primarily in the Twin Cites and the southeast and south central regions of the state.

Q. How long do they feed?

A. JB emerge about July 1 each year and are active through September. They have been reported as late as October during late falls.

Q. Are there any non-chemical methods for managing JB?

A. The best method is physical removal. A good way to do this is to take a pail of soapy water and brush them off or pick them off by hand so they end up in the pail. The soapy water kills them. If you just knock them off plants, they will fly and return to them. It is best to do this right away in the morning or in evening when they are less active.

Q. Are there any low impact products I can use on JB?

A. There are a couple you could consider. Products containing Neem are reasonably effective, especially when JB numbers are low to moderate. They act as an antifeedant to deter JB from feeding on plants. Pyrethrins containing PBO (Piperonyl butoxide) is also effective. Both products need to be reapplied fairly frequently.

Q. What residual insecticides can I use to treat JB?

A. Neonicotinoid insecticides, especially imidacloprid (various trade names) and dinotefuran (Safari) are good choices. They are systemic, are easy to apply, and are long lasting. They do not kill JB quickly but they do cause them to stop feeding with death coming later. One important drawback of these products is they are very toxic to bees. Avoid treating trees and shrubs, like linden and roses, that are attractive to bees. It doesn't matter that the trees and shrubs are not flowering at the time of application as these insecticides will be active for a year.  Another consideration is that it takes some time, especially for imidacloprid, for the tree to take up the insecticide.  You need to factor this lag time when using these products.

There are also a variety of residual insecticides that you spray directly onto the leaves that are effective, including pyrethroids like permethrin, bifenthrin, esvenfalerate, and lambda cyhalathron, and carbaryl. Be sure that the foliage is throughly treated.

Trees and shrubs are best treated as soon as damage and JB are first noticed. Since they have had about a month to feed, you should consider how much damage has already occurred if you are still thinking of treating. If over half of the tree or shrub has been defoliated then it probably not worthwhile to treat it any more this year. If at least half of the tree or shrub is green, then there is still value to use insecticides to help protect trees.

Q. What can I spray on food plants, like apples and raspberries.

A. There is not a simple answer to this as one active ingredient, such as permethrin, may be labeled for food plants on one product but may not be on another. People need to check to see if the particular food crop you intend to treat is on the label of the specific product you want to use. If it is, then you can use that insecticide to spray your desired edible plant. Then be sure to observe the interval between when you spray and when crops can be harvested.

If the crop you want to treat is not on the label, then don't spray it. Check the label before you buy a product and again before using it to be sure you know what plants can be treated.

Q. How effective are JB traps?

A. JB traps can catch what appears to be an impressive number of JB. However, research shows that they actually draw more JB into the area than what they catch. The result is you not only do not reduce JB adults and their damage but you actually increase the amount feeding damage that occurs to susceptible plants.

Q. How effective is it to treat my turf to prevent JB adults from getting into my garden?

A. Treating for JB grubs does not protect your yard from adult beetles. Adults are very mobile and can easily fly in from outside your property. Only treat your lawn if you are seeing damage from the grubs.

Click here for more information on Japanese Beetles.

Karl Foord, UMN Extension Educator

While photographing lilies for the article "Lilies - One of the Queens of the Garden," I came upon a blue butterfly (perhaps a Spring Azure Celastrina sp.). I was hoping to photograph it when it had opened its wings. I slowly drew closer only to realize that it was not to open its wings again. It was in the grasp of a flower spider (perhaps a Goldenrod Spider or "Red-spotted Crab Spider" Misumena vatia).

A smaller spider perhaps a male of the species jumped on top of the other spider and then fled. I would expect this was a wise thing to do. This spider was particularly well camouflaged on this Lilium 'Heart's Desire' Asiatic Lily. Flowers are beautiful, nutritious and dangerous, depending on your point of view.

Jeffrey Hahn, Asst. Extension Entomologist

The Asian longhorned beetle (ALB), Anoplophora glabripennis, was recently found for the first time in Ohio, 30 miles southeast of Cincinnati. This exotic borer, originally from Asia from southern China, Korea, and Japan, was first found in North America in 1996 in New York. Two years later it was found in Chicago (but was eradicated there). Since then, it has also been discovered in New Jersey (2002), Toronto (2003), and Massachusetts (2008) before being found in Ohio.

This is a good reminder to be watching for ALB in Minnesota. Although it has not been discovered here yet, we have a lot of trees this borer loves to attack, including maple, American elm, and willow. It is important for people to be familiar with ALB so suspicious insects can be reported. In Ohio, a private citizen found insects in three maples that she thought could be ALB and reported it to entomologist at Ohio State University who then passed this on to USDA-APHIS for verification.

The best way to recognize ALB is from the adults. They are large insects, ranging in size from 1 - 1 ½ inches long (not counting the antennae). Like other long-horned beetles, ALB has antennae that as long or longer than its body, up to four inches in length. ALB particularly has distinctive black and white banded antennae. It's body is a glossy black with as many as 20 white distinct spots on it. Because of this, ALB is sometimes called the starry sky beetle. Adults are active throughout the summer and into the fall.

Don't confuse ALB with the whitespotted sawyer, a native long-horned borer in Minnesota. A whitespotted sawyer is about 3/4 - 1 1/4 inches long and has a dull black body with indistinct white spots or patches. Males lack any banding on their antennae while females possess only faint bands. Whitespotted sawyers are associated with conifers.

You may see ALB larvae in wood. They are legless and cylindrical in shape with a head that just sticks out of the body. They are large, growing up to two inches in size. These larvae create oval tunnels as they bore into the sapwood and heartwood. Although it is easy to identify ALB as a type of roundheaded borer (the larvae of long-horned beetle), it is difficult to identify roundheaded borers as ALB.

If you have maple, elm, or willow in your yard or other hardwoods like birch and poplar, watch for signs of infested trees. Because ALB is such a large insect, when it emerges as an adult, it creates a large, 3/8 - 3/4 inch wide round exit hole in the trunk or branches. This large enough to stick the eraser end of a pencil into the hole. Other potential signs of ALB include sawdust on the ground or the fork of branches, sap oozing from the exit holes, and the presence of small oval to round shallow pits chewed into the trunk or branches - the females chew these for a place to lay eggs.

If you think you have found ALB, contact the Minnesota Department of Agriculture's "Arrest the Pest" Hotline at 651-201-6684 (Metro Area) or 1-888-545-6684 (Greater Minnesota).

Jeffrey Hahn, Asst. Extension Entomologist

Immature earwigs were have been seen in gardens recently and will soon turn into adults. Many areas of Minnesota experienced high earwig numbers last year. Be on the watch for them in your garden this summer. Earwigs are about 5/8 inch long, with a flat, reddish brown body and very short wings. They look like a cockroach or a rove beetle but are distinctive because of the pair of pinchers (cerci) on the tip of their abdomen. Nymphs are similar to adults except they are smaller and generally lighter in color.

Earwigs are most active at night and like to hide during the day in dark, tight, damp areas, like under potted plants, cracks between bricks and pavers, and on plants in buds and folded leaves. Earwigs are scavengers, feeding on damaged and decaying plant matter as well as weakened or dead insects and other small organisms. Earwigs can also feed on healthy plant material. This is when they can become a problem in gardens.

Earwigs can damage flowers, like dahlias and marigolds, chewing irregular holes in flower blossoms and in leaves. They are also reported to attack various vegetables, corn silk, and seedlings. Some of this damage can be confused with slug feeding. However, slugs leave a slime trail while earwigs do not. If you are not sure what is causing the damage you are finding, go outside at night with a flashlight check under plants for earwigs and other pests.

To reduce the number of earwigs around your garden, clean up debris that earwigs can hide under, such as leaves, plant debris, bricks, piles of lumber, and similar things. It can also be useful to thin out or remove mulch. You can also set out rolled up newspapers to trap earwigs. Put them into your landscape or garden during evening. In the morning shake the traps above a pail of soapy water to remove the earwigs.

Minimize excess moisture in the landscape. Be sure that the landscape has good drainage and that irrigation systems are working properly. A good strategy when watering is to irrigate more thoroughly and deeply but less often so the surface of the soil remains drier.

You can also protect plants with an insecticide application. An effective method is to treat the surrounding mulch where the earwigs are hiding. Use a drench, e.g. lambda cyhalothrin or carbaryl for this. You may need to attach the product to a hose to get sufficient volume. You may also be able to protect individual plants by applying a spray, e..g. permethrin, deltamethrin, or acetamiprid or a dust, e.g. permethrin or deltamethrin, to plants when damage is first noticed.

Jeffrey Hahn, Asst. Extension Entomologist

There have been questions lately about winged ants being found in and around homes and other buildings. Nearly all ant species in Minnesota (Pharaoh ants are an exception to this) produce mating swarms, i.e. winged males and females, at certain times of the year. These reproductives emerge and fly out of the nest, typically in large numbers. The males die shortly after mating with queens. The queens fly off in search for a suitable place to start a nest, although the vast majority do not survive long, being eaten or succumbing to the elements.

Upon landing, the queen breaks off their wings. As she starts construction of the nest, she lays a batch of eggs which she cares for until they mature into adults. From that point on, the workers assume all of the work responsibilities and the queen's sole job is to lay eggs. She is taken care of by worker ants and remains in the nest her entire life.

In Minnesota, there are two common ants that people see swarming in the spring, carpenter ants and pavement ants. Carpenter ant queens are typically black and large, about ½ inch long, although some species are smaller and can vary in color. However all carpenter ants have a one segmented node between the thorax and abdomen. Pavement ant queens are about 1/4 - 3/8 inch long, brownish and has a two-segmented node.

Finding a swarm of ants indicates a nest is nearby. However, a swarm, in and of itself, is not necessarily a problem. For the most part, like when they are found in your yard, they are not anything more than a nuisance. Under these circumstances, just ignore them until they go away on their own.

If winged ants are found indoors, then there is a nest inside the home. Correctly identifying the ant species will help determine the best control. Pavement ants nest in the soil under objects, like sidewalks, driveways, stones, and concrete slab construction of homes. When found inside, they are annoying but are not a structural problem. The only necessary control when pavement ant swarmers are inside is to physically remove them, especially if you only see winged ants and not any workers

Finding winged carpenter ants indoors is another matter. They nest in water damaged wood and can potentially damage buildings. You can be somewhat patient when trying to determine where they are coming from and attempting control but you should not ignore them indefinitely. Their elimination is best done by a professional pest management company.

However, sometimes a wingless carpenter ant queen is found walking around in or around a home. Because it is a carpenter ant, people are concerned about a nest being in the home. But remember that this queen has not established a nest yet and is still looking for a place to begin one. Her presence does not mean a colony is in the home. The only necessary control is to dispatch her.

Jeffrey Hahn, Asst. Extension Entomologist

There are two common species of tent caterpillars that are now active in Minnesota, eastern tent caterpillars and forest tent caterpillars. Both normally hatch closer to early May, but the cool spring weather we have experienced has slowed down their emergence and they only first started to appear closer to the middle of the month. Here is how you can distinguish between these insects.

Eastern Tent Caterpillars

This insect is easy to identify because it constructs silken webs in the fork of branches as soon as they young larvae hatch. The caterpillars feed outside of the tents on leaves during the day (as long as the weather is nice) and return to the webbing at the end of the day and during rainy weather for protection.

The caterpillars are bluish black with yellow and a white stripe running the length of the top of its body. They are also mostly smooth except for a series of hairs sticking out along the side of their bodies. They are two inches when fully grown.

Look for eastern tent caterpillars on hardwood trees, particularly fruit trees, like apple, chokecherry, crabapple, plum, and cherry. Eastern tent caterpillars are common most springs. They maintain relatively steady populations from year to year and generally do not occur in outbreak numbers.

Forest tent caterpillars

Also known as armyworms, forest tent caterpillars are familiar insects in the north and central areas of Minnesota. These caterpillars are blue and black with distinctive footprint or keyhole shaped white spots on their backs. They are mostly smooth except for hairs that stick out along the sides of their body. They grow to be two inches long when fully grown. Despite their name, they do not make conspicuous webs on trees.

Forest tent caterpillars feed on many deciduous trees, including aspen, birch, maple, crabapple, apple, ash, oak, and elm. They go through cycles of tremendously large numbers, lasting 5 to 8 years, before collapsing to such low numbers that they are not noticed. Periods of low populations lasts about 8 to 13 years. Forest tent caterpillars peaked in 2002 and their numbers have since crashed.

The Minnesota Department of Natural Resources (DNR) reports that in 2010 just over 70,000 acres were defoliated, primarily in the middle one-third of Minnesota in a crescent that extends from south of Mille Lacs Lake through St. Cloud to Wilmar and up through Detroit Lakes. There were also a few isolated areas of defoliation in Hubbard, Cass and Crow Wing Counties. Forest tent caterpillars are also found in the Twin Cities area. Their numbers are expected to increase some in 2011 compared to last year but an outbreak is not expected.

Management

The decision to treat tent caterpillars should be made based on several criteria. First, consider what percentage of leaves have been eaten. If only a few branches are affected, the tree can tolerate that damage. Leaf feeding tends to be more a cosmetic problem and not one that threatens the health of the tree. Even if defoliation is severe, healthy, well-established trees can withstand this feeding in a given year. However, young trees are less tolerant and should be protected. Unhealthy, stressed trees should also be protected from severe defoliation.

Another important consideration is the size of the insect. Ideally these insects should be treated when they are 1/2 their full-grown size or smaller, i.e. about one inch in size. The larger they are, the closer they are to being done feeding. Because the tent caterpillars emerged later than usual, they are not as far as long as they would normally be by the beginning of June. There is still time to treat them and minimize their defoliation. However, if by the time you see them, the are close to two inches long, it is not worth treating them.

There are a variety of residual insecticides that you can use if it is desirable to protect your trees. Consider using products that have a low impact on the environment, such as Bacillus thuringiensis, spinosad, and insecticidal soap. Bacillus thuringiensis is a particularly good product if the tree is flowering since it will not harm visiting honey bees.

Photo 1, Karl Foord.

Karl Foord, UMN Extension Educator

Keep an eye out for tent caterpillars and Pine sawfly larvae. Look for shriveled and missing needles on pine branches just below the newly forming candles (Photo 1). The larvae are gregarious and form in numbers on these sections of the plant. They are quite voracious and can strip a tree quickly (Photo 2). It is best to wash them off the plant with water rather than to use an insecticide. See Jeff Hahn's article for a more detailed account of pine sawfly.

Pine sawfly larvae exhibit some fascinating forms of defensive behavior. Colonies of larvae will rear their heads in unison when disturbed. This behavior may serve to startle potential predators (http://www.youtube.com/watch?v=vve7BtXh3Vw).

Pine sawfly larvae also collect pine resin in a special gut compartment as they feed. When

Photo 2, Karl Foord.

attacked by a predator, the larva will regurgitate a droplet of pine resin and try to dab it on the predator. Ants and other predatory insects will often abort the attack and try to remove the sticky resin by cleaning behavior.

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Andrenid bee. Jeff Hahn.

Andrenid bees, especially Andrena spp., are common insects that are sometimes seen in yards and gardens in spring. They are small to medium sized insects, about 1/4 - ½ inch long. They are hairy, dark-colored insects, often with a thick mat of yellow hairs on their thorax.

They typically overwinter as pupae and emerge as adults as soon as the weather becomes warm, living for about a month. Andrenid bees nest in the ground, preferring sunny, dry sites with sparse grass or few plants. They create cylindrical tunnels where they spend essentially their entire life preparing these nests for their young. They provision them with pollen balls on which the larvae feed during summer.

Unlike honey bees and bumble bees, which are social insects living in colonies, andrenid bees are solitary insects that live by themselves. They are responsible for all of the work that is required to maintain the nest and provide for the larvae. However, andrenid bees typically live gregariously, i.e. many individual nests in a small area despite the appearance that they are coming from a single nest.

Photo 2: Andrenid bee nests (notice how many there are in this small area). Jeff Hahn.

Fortunately, andrenid bees are gentle and stings are extremely rare. It is possible they might sting if they are mishandled. However, there are many reports of people in close proximity to these bees without being stung.

When dealing with andrenid bees, tolerate them as much as possible. Bees are beneficial because they are pollinators and should be preserved whenever possible. Remember that they are gentle with little risk of stings. They are also only active for about a month and they shouldn't be around much longer this spring. Insecticides are a possibility but should only be used as a last resort.

Photo 3: Cuckoo bee, Nomada sp., entering an andrenid bee nest. Jeff Hahn.

There is a plot twist in one particular andrenid bee site that was observed recently. Another insect was apparently nesting in the ground in same area as the andrenid bees. They were reddish brown with a yellow striped abdomen, few hairs on their bodies, and were a little smaller. After collecting and examining a specimen, they were identified as cuckoo bees, Nomada sp. Cuckoo bees are wasp-like in appearance and are not pollinators like most bees. Instead they are parasitic on other bees, entering and laying their eggs into the host bee's nests so the food gathered will feed the cuckoo bees' young. The world of entomology never ceases to amaze.

Jeffrey Hahn, Asst. Extension Entomologist

With a stroke of his pen, Governor Mark Dayton signed a proclamation officially declaring May 22 - 28 as EAB (Emerald Ash Borer) Week in Minnesota. This is a good opportunity to remind people that EAB is still a serious pest that threatens our state's nearly 1 billion ash trees. That week also corresponds with the official start to camping season as people travel for the Memorial Day weekend.

Photo 1: Adult emerald ash borer. Jeff Hahn.

The theme for EAB Awareness Week is 'Keep our trees safe. Use MDA (Minnesota Department of Agriculture) certified or local firewood.' This is such a critical message for people to understand that the one of the most important methods for EAB to be transported into areas that are uninfested is through firewood. That is why people are strongly encouraged to leave their firewood at home and buy from local, approved firewood vendors.

Currently EAB is known only in Ramsey, Hennepin, and Houston counties. MDA has enacted quarantines in these counties to try to prevent infested ash product from moving out of these areas and into uninfested sites. To supplement this effort, MDA also continues to conduct surveys using purple traps to try to detect EAB soon after it enters an area. They have also enacted management strategies to slow the rate of spread of EAB

Citizens can also help by reporting insects they suspect are EAB and potentially EAB infested ash trees. If you think you have discovered EAB go to this step by step guide. If you can still can not rule this invasive pest out by the end of the page, then contact the University of Minnesota Forest Resources Extension who will put you in contact with someone that can help you determine whether you have EAB.

For more information on EAB, see the University of Minnesota Extension EAB web site.

Jeffrey Hahn, Asst. Extension Entomologist

The Minnesota Department of Health (MDH) recently issued a news release detailing the marked increase in the number of tick-borne diseases in 2010. MDH tallied 2,069 cases of Lyme disease, Human anaplasmosis and babesiosis from last year. While the number of Lyme disease cases only went up a little, Human anaplasmosis cases more than doubled and instances of babesiosis were nearly twice as much compared to 2009.

Photo 1: Adult female blacklegged tick. Jeff Hahn.

Blacklegged ticks (formerly known as deer ticks) is the species responsible for transmitting these diseases. The highest risk areas in Minnesota are in the eastern, central, and southeast areas of the state. Symptoms are variable. When dealing with Lyme disease, many cases (but not all) exhibit a red, circular, bull's-eye rash. Other disease symptoms can range from no reaction to arthritis, neuropathy, headaches, fevers, chills, and muscle aches, joint swelling, cardiac and nervous system problems, and, in a few cases, death. For more information on tick-borne disease, see the Unversity of Minnesota Extension fact sheet, Tick-Borne Diseases in Minnesota.

The risk of disease can occur any time from spring through fall. Take the proper precautions to protect yourselves from ticks.

- Avoid areas where ticks are likely to be found. Particularly stay on trails and avoid walking through woody, brushy, or grassy areas where ticks are most common.

- Wear protective clothing, such as long-sleeved shirts and long pants. Wear light colored clothes so it is easier to see ticks on you. For added protection, tuck pants inside socks.

- Use repellents for additional protection. Apply them to socks, pant legs, and parts of clothing that may brush against vegetation. DEET and permethrin are effective. Apply DEET to clothing and skin but apply permethrin only to clothing.

- Be sure to check your clothes and yourself when you have been outdoors in known tick areas. Save any suspected blacklegged ticks for identification.

When dealing with ticks in your yard, do the following:

- Keep grass and vegetation short around homes, where it borders lawns, along paths, and in areas where people may contact ticks as ticks are less likely to survive in short grass.

-. Remove leaf litter and brush, especially in areas where the lawn borders grassy, brushy areas. Also prune trees and shrubs in these areas to allow more sunlight through as ticks are more common in shaded areas.

- When large numbers of ticks are present in areas adjacent to home yards, you can treat the edges of wooded or brushy areas and paths to help reduce tick numbers. Use an insecticide labeled for a turf area, such as those containing permethrin, cyfluthrin, or carbaryl. Do not spray such an area more than once a year.

- It is not necessary to treat your lawn for ticks as ticks rarely infest maintained yards.

For more information on Minnesota Ticks, see the University of Minnesota Extension fact sheet, Ticks and Their Control.

Jeffrey Hahn, Asst. Extension Entomologist

An interesting insect, found under unusual circumstances, was reported recently. A gentleman had a large dead branch pruned out of his maple in February. It had rotted in the center and was a hazard that needed to be removed. He cut the limb into smaller pieces and stacked them in April. He noticed in one branch section where the wood had rotted an accumulation of mud.

Photo 1: Rat-tailed maggots. Kyle Jensen.

He removed the mud and uncovered several pinkish larvae with long 'tails'. They were legless with no obvious head. These insect larvae are rat-tailed maggots, Eristalis spp. The most commonly encountered species is Eristalis tenax. The body of a mature rat-tailed maggot is about 3/4 inch long with the telescopic breathing tube (the 'tail') as long as two inches. This insect belongs to the family Syrphidae which are commonly called flower flies or hover flies because adults are typically found around flowers and are able to hover in place when flying.

Rat-tailed maggots typically live in stagnant, low oxygenated water with high levels of organic matter. They have been found in sewage water, manure pits, and other types of polluted water as well as ponds with a lot of algae. They are also commonly found in rotting, decaying organic matter, including animal carcasses, damp compost, and wet, decaying leaves.

They are essentially harmless to people, although there have been some reported cases where they are involved in myiasis, i.e. infesting living tissue of people and animals. Rat-tailed maggots in particular would infest gastrointestinal tissue. Fortunately, this would be considered extremely rare and unusual in Minnesota.

There is not a good explanation for why these rat-tailed maggots were found in the rotting limb of a tree. There is a precedent for rat-tailed maggots being associated with moist, decaying plant matter so it is somewhat conceivable for them to be found in rotting wood. But for them to spend their lifetime in the rotting center of a tree limb still attached would be considered unusual at best.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Photo 1: Don't worry about wasps in this nest in early spring. Jeff Hahn.

As our attention finally turns to spring, there could be some loose ends to tie up from last fall. For people that experienced wasp nests in their home, they may be wondering what they should do with any wasps that may remain in them. Fortunately, there are no longer any wasps alive in those nests.

Late last summer, new queens were produced. After mating, they left the nest, and flew off to eventually find sheltered sites in which to overwinter. Meanwhile back at the nest, the old queen and workers continued with their daily routines until freezing weather killed them. Newly mated queens do not return to their old nests but instead will construct their own nests when spring begins.

So what does that mean for nests in and around your home this spring. You can largely ignore them. One exception to this would be if you experienced a wasp nest in a wall void or somewhere within the structure of your home, such that you could not see the nest but you can see wasps flying back and forth from an opening. In this case, you should seal up those openings. The reason is that while the old nest is not reused, a new nest could be built in the same space. Early spring is a good time to seal those openings before wasp queens are active and begin building new nests.

Photo 2: Paper wasps overwinter gregariously. Jeff Hahn.

There are have also been reports of wasps indoors during mild late winter days. There has been concern that there is a wasp nest in the home and the warm temperatures are 'waking' them up. While most wasp queens will overwinter on their own, paper wasp (Polistes spp.) queens seek shelter gregariously, i.e. in nonsocial groups. It is not uncommon to see a dozen or more paper wasps but fortunately, this is not an indication of a nest. If you encounter this situation, just open the window and let them fly out or take a fly swatter or rolled up newspaper and dispatch them.

Jeffrey Hahn, Asst. UMN Extension Entomologist

The most common small moths found indoors, e.g. Indianmeal moths, are usually associated

Photo 1: Webbing clothes moth adult Jeff Hahn.

with stored foods. However, occasionally you may encounter small moths that attack fabric. The most common species is the webbing clothes moth. The adult webbing clothes moth has buff colored wings with no spots or markings on them. The wings are folded behind their back when at rest and the insect measures about 1/4 to 1/3 inches long. Particularly characteristic is the mop of reddish brown hairs on its head. Webbing cloth moth adults avoid light and generally seek out dark areas of rooms.

The larvae are whitish with dark colored heads and are no larger than ½ inch long. They feed on wool, fur, feathers hair, and other materials of animal origin. They are not interested in plant material, like cotton and generally do not attack synthetic material unless it is blended with wool or is stained, e.g. with sweat or food. Webbing clothes moth larvae graze on the surface of the material, creating irregular holes in the fabric. They also create silken tubes or mats on the fabric as they feed which helps to identify the damage.

Prevention is the best control to avoid webbing clothes moths. You can do this through regular vacuuming including carpets and rugs, along baseboards, under furniture and in closets as well as removing scraps and remnants of wool, fur, and similar materials. Regularly inspect susceptible clothes, like wool sweaters and suits, wool rugs, animal mounts, and other material for signs of infestation; the sooner an infestation is discovered, the sooner it can be controlled.

When putting susceptible clothes away for the summer be sure they are dry cleaned or

Photo 2: Webbing clothes moth damage, adult and larva. Clemson-USDA.

laundered. It best to place them in airtight containers, such as a plastic sweater box. Wood chests can also work if the top fits tightly. For added protection, you can place mothballs or crystals (naphthalene) with the clothes in the storage containers. However, keep in mind the smell of naphthalene may be challenging to remove from clothing. Dry clean clothing again before wearing to help remove any odor. Remember that naphthalene is not a repellant but instead uses a concentration of vapors to kill insects. Placing moth balls or crystals loose in a closet or similar areas will not prevent webbing clothes moths. Cedar chips, although popular as an insect repellent, do not effectively deter webbing clothes moths.

If you find an infestation of webbing clothes moths, either remove and throw away the source of the infestation or have it laundered or dry cleaned. Be sure to vacuum or other wise clean up the immediate area to remove any potential additional sources of infestation. Severe webbing clothes moth infestations may require the service of a pest management service.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Photo 1: Boxelder bug. Jeff Hahn .

It is common during mild winter weather to see various nuisance insects in your home, especially boxelder bugs, multicolored Asian lady beetles, and western conifer seed bugs. Despite the appearance that they have laid eggs and are hatching now, these insects have actually been in homes since fall when they first entered structures.

When they came into buildings in the fall, some insects accidentally moved all the way into homes. Others took refuge in wall voids, attics, and other nooks and crannies. As long as these areas stayed cold, they remained inactive. However, when it became warm, they 'woke up' and moved towards warmth which would be the inside of your home. As we get closer to spring, we see this occurring more frequently. These insects often congregate together in clusters in these harborages so as these areas warm up, not all of the insects become active at the same time. Or they just could occur in places in the home that warm up at different times. The end result is that there will be insects emerging up at different times during the winter.

When you see these insects now, your options are limited. Your best bet is to physically remove them, e.g. with a vacuum. Insecticides are generally not suggested as it will not prevent the insects from emerging and you have to physically remove them whether they are dead or alive. If this is a problem you deal with every year, be sure to target control in the fall before the insects start moving inside. The best tactics are sealing as many obvious spaces that you can find and supplementing that with an insecticide treatment. Once these insects are in your home, there is little you can do.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Photo 1: Check out this new EAB fact sheet. Jeff Hahn .

A four page fact sheet entitled Frequently Asked Questions Regarding Potential Side Effects of Systemic Insecticides Used To Control Emerald Ash Borer was recently completed.  This publication was written by entomologists at the University of Ohio State, Michigan State University and University of Minnesota Extension and reviewed by 14 specialists.  It was produced to help answer common questions people have about the insecticides used to treat emerald ash borer using the most current research based information.  As emerald ash borer becomes more widespread in Minnesota (and other areas of the country) and insecticides are considered, more people will have these questions and need access to unbiased, fact-based information.  You can find this publication at the following link. 

Jeffrey Hahn, Asst. UMN Extension Entomologist

When living in Minnesota, we know that mosquitoes are a fact of life. However, we at least

Photo 1: Anopheles punctipennis. Bunni Olson.

can take consolation that this is a problem during the summer and not something we need to deal with in the dead of winter. And yet, a homeowner e-mailed that she was finding odd insects in her home that she said looked just like mosquitoes. She sent an image that showed what looked like a mosquito but with banded wings. Mosquitoes typically do not have banded wings but there are some closely related insect groups, like crane flies, that commonly do.

However, the long proboscis (mouthparts) and scales on its wings give the insect away as a mosquito. You can identify it as female because its antennae with few hairs on it and is not feather-like as a male would be. You can even identify the mosquito as an Anopheles sp. from the long palps adjacent to the proboscis. The wings have alternating black and light colored patches on their wings which are distinctive and diagnostic for the species Anopheles punctipennis (no common name).

Anopheles punctipennis, like other Anopheles species, spends winters in Minnesota in a diapause, a period of inactivity somewhat similar to hibernation. In fall, this species seeks dark, quiet, protected areas and commonly are found in abandoned buildings, hollow trees, caves, garages, and basements where they would normally stay for the winter. For individuals overwintering indoors, it is possible for some movement by a person or pet near to where they are resting to cause them to become active. Fortunately, Anopheles punctipennis is not known to transmit any disease and in fact are very unlikely to even bite now. They are just a nuisance and you do not need to take any special control measures against them.

Jeffrey Hahn, Asst. UMN Extension Entomologist

A position statement was released in January strongly advocating the conservation of ash as a part of an integrated pest management program, along with tree inventories and strategic removal / replacement of unhealthy ash. Cost-effective, environmentally sound emerald ash borer (EAB) treatment protocols are now available that can help preserve ash trees. This document is supported by a combination of university scientists with expertise in EAB management, commercial arborists, municipal foresters, public works officials, and non-governmental organizations (NGOs).

This is a very important document that should help guide us as we deal with EAB in Minnesota. Below is the text for the document. To see the original document, click here, http://www.emeraldashborer.info/files/conserve_ash.pdf

Coalition for Urban Ash Tree Conservation
- Emerald Ash Borer Management Statement -

Emerald ash borer has killed millions of ash trees since its discovery in 2002 and the number of dead ash is increasing rapidly. Ash species are abundant in planted and natural areas of urban forests, representing 10 - 40% of the canopy cover in many communities.

Ash trees provide substantial economic and ecosystem benefits to taxpayers, ranging from increased property value, to storm water mitigation, to decreased energy demands (http://www.coloradotrees.org/benefits.htm) ( this link is no longer available).

Consequently, widespread ash mortality in urban forests and residential landscapes is having devastating economic and environmental impacts. Indeed, EAB is predicted to cause an unprecedented $10-20 billion in losses to urban forests over the next 10 years. (http://ncrs.fs.fed.us/pubs/jrnl/2010/nrs_2010_kovacs_001.pdf)

After its initial discovery, regulatory agencies attempted to eradicate EAB through removal and destruction of all ash trees in infested areas. Unfortunately, this proved unsuccessful and was soon abandoned.

Photo 1: Ash stumps in park in Michigan cut down due to EAB. Jeff Hahn.

Since then, university scientists have developed and refined treatment protocols that can protect healthy ash trees from EAB and help conserve the urban forest. However, despite availability of cost-effective treatments, many municipalities, property managers, and homeowners continue to rationalize tree removal as the only viable management strategy for EAB. This is based on erroneous beliefs that tree removal slows the spread of EAB, or that treatment is not effective, economical, or environmentally sound. Current science supports conservation via treatment as a sensible and effective tool for managing healthy ash trees in urban settings. In many cases, tree conservation is economically and environmentally superior to tree removal.

Based on research conducted by university scientists, and careful review of the potential impacts on human health and the environment, the Environmental Protection Agency (EPA) has registered three systemic insecticides for control of EAB - dinotefuran is registered for basal trunk bark or soil application, emamectin benzoate for trunk injection only, and imidacloprid for soil application or trunk injection.

When applied using formulations, products, and protocols documented as effective by university research, these treatments can provide environmentally sound control of EAB, sufficient to maintain a functional and aesthetically pleasing ash canopy.

Treatment is most appropriate after EAB infestation has been detected within 15 miles, and is most effective when applied before trees are infested. However, treatment can also save ash trees with a low level of EAB infestation. Spring is the ideal time for treatment, but soil application in fall can be effective in some situations.

Different treatment regimens will be optimal under different situations -- no one treatment plan or application method is best under all circumstances.

A program of sustained treatment will be needed to conserve trees through peak EAB infestation. However, as the local EAB population declines due to death of untreated ash, it is possible that treatment frequency may be reduced. Research on this question and other aspects of EAB management is ongoing, requiring practitioners to stay current.

Up-to-date information about EAB insecticides, application protocols, and effectiveness can be found at: http://www.emeraldashborer.info/file/multistate_EAB_Insecticide_Fact_Sheet.pdf

In summary, urban ash conservation can be less costly than removal, especially when the significant environmental and economic benefits of established trees are considered (www.treebenefits.com, http://extension.entm.purdue.edu/treecomputer/). Furthermore, ash conservation can circumvent the substantial environmental impacts caused by wholesale deforestation of the urban landscape, as well as the documented public safety risks associated with standing dead ash trees and their removal. [See original document (link above) for authors and their affiliations]

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Bed bugs. Jeff Hahn.

A common call that has been received recently has been from people that have been experiencing bites of an unknown source. It is challenging to correctly diagnose these problems. It is important to know that unknown bites can be the result of insects as well as non-insect causes. If it is an insect infestation, the most common causes are bed bugs and fleas.

Bed bugs have been on the increase over the last 10 or so years. Adult bed bugs are about 1/4 inch long, brown, and similar in size and shape to wood ticks; newly hatched bed bug nymphs are about 1/16th inch long or about the size of a pinhead. Bed bugs like to hide during the day and generally prefer to bite at night so it's possible to be bitten and not realize it. When looking for bed bugs, first check out bed rooms and other places where people sleep or rest. Other good areas to look are places where luggage is stored.

Bed bugs like to hide in cracks and behind or under objects so examine closely around mattresses, boxsprings, bed frames, as well as dressers, desks, chairs, and other furniture, the edges along carpeting and behind clocks, pictures, and baseboards. Also be aware of signs of bed bugs in your home. In addition to bites, watch for cast skins (empty shells of insects) as well as dark (but not red) spots. These spots are fecal droppings, composed of digested blood. Look for these spots on sheets, bedding, or other places where bed bugs feed or around their hiding places.

You can also try to determine whether bed bugs are present by using a bed bug interceptor. They are small plastic trays with an inner and outer ring. Put them under each leg of your bed. Bed bugs that attempt to climb up from the floor to the bed become trapped in the outer well. Any bed bugs that try to climb down will become trapped in the inner well. You can purchase Bed bug Interceptors online (type "bed bug interceptor" into a search engine for sources).

Fleas have been an increasing problem in the last few years. They may be present in homes

Photo 2: Fleas. Nancy Hinkle, Univ. of Georgia.

regardless of whether you have pets or not. An adult flea is small, about 1/8th inch long and dark colored. It's body is flattened from side to side and it has long back legs for jumping. Because of their size and shape, they can easily hide in cracks and crevices and not be seen.

To determine whether you have fleas infesting your home, try the white socks test. Walk slowly through a room where you suspect fleas wearing a pair of white socks. Fleas are attracted to the vibrations from the walking and the warmth of the person and will jump towards the ankle. Their dark colored bodies show up plainly against the white background of the socks. Particularly check areas where pets spend a lot of time (if they are present).

While bed bugs and fleas are the most common biting insects there are other possible causes. Head lice, mosquitoes, as well as insect relatives, such as bird mites, like northern fowl mites, chiggers, and rodent mites, such as tropical rat mites, can potentially be problems. During winter however, mosquitoes, bird mites and chiggers are not active and are not possible causes. Head lice are most common on children and are restricted to the head (it is possible to find body lice which are located on the body as well as clothing and bedding. However, they are rarely a problem). Rodent mites can be encountered, although this rare. In one case, a tropical rodent mite problem was infesting a pet guinea pig and was biting the people in the house. Dust mites do not bite people; they are problem because of the allergic reactions to them by individuals.

If you are not clear whether you have an insect or mite problem in your home, consider having an experienced pest control company inspect your home. You could also submit any suspicious insects to your local county extension office for identification. Under no circumstances should you use insecticides in your homes if you can not confirm a biting insect or mite problem.

However, if you do not find any evidence of biting insects or mites, it is very important to consider non-insect explanations. There are a variety of causes that can explain insect-like bites or irritations that are unrelated to insects or mites. Some of these possibilities can include dry air, allergic reactions to personal or household products (e.g., detergents, soaps, cosmetics, clothes, jewelry), environmental contaminants, microscopic fibers (e.g. insulation or paper fibers), certain health conditions (e.g. diabetes, neurological, liver, or kidney disorders), or even stress.

Photo 3: Fibers and blood thought to be biting insects. Jeff Hahn.

There is also a condition known as delusory (or delusional) parasitosis, also called Ekbom's syndrome. This is a very real condition where sufferers have the mistaken belief that they are being invaded by parasites even when presented with evidence to the contrary. Typically, people suffering from delusory parasitosis have been battling this problems for months, sometimes even years. Commonly they have had pest control technicians search their homes for pests but without find anything that would be biting. They often have tried a variety of solutions, including pesticide applications, but if there is any relief it is short-lived. Some sufferers have even thrown out their furniture, even moved, to tried to escape this problem. Of course this action is not successful.

People that are experiencing unknown bites that can not confirm an insect or mite problem should see a family physician for help in diagnosing their problem. They should work with an entomologist to verify or rule out insects. For more information on unknown bites and delusory parasitosis see the following web pages, http://www.ca.uky.edu/agc/pubs/ent/ent58/ent58.pdf http://delusion.ucdavis.edu/delusional.html and http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7443.html

Jeffrey Hahn, Asst. UMN Extension Entomologist

Bed bugs are often a very challenging and costly problem with which to deal. The best long-term control is to hire an experienced professional pest control company to treat your home. They have the expertise, experience and effective products to properly control bed bugs. These insects are too difficult for a homeowner to eliminate themselves. However, while you cannot eradicate bed bugs are your own, there are some steps you can take to help reduce their numbers.

Make Sure You Have Bed Bugs

Not every insect you see is necessarily a bed bug. Especially with all of the media attention recently, it is easy to think that you see bed bugs in every crack and crevice in your home so be sure you know what they look like. Despite what some people believe, bed bugs are not microscopic. Adults are similar in size and shape to a wood tick. They measure about ¼ - 3/8 inches long and are oval, flattened, brown, and wingless.. Young bed bugs are much smaller; when they first hatch, about 1/16 inches long and are nearly colorless except after feeding, but are oval like adults. If you have any doubts, let an expert identify your insects to be sure they are bed bugs.

Photo 1: Bed bug adult. Jeff Hahn.

The best places to look for bed bugs are the bedroom or other rooms where you may rest or sleep or where you set down or store your luggage. Bed bugs like to hide in cracks and behind or under objects so examine behind baseboards, mattresses, boxsprings, bed frames, as well as dressers, desks, chairs, and other furniture, the edges along carpeting, and behind clocks and pictures. Consider having an inspection done by an experienced pest control company.

Be aware of signs of bed bugs in your home. One of the first indications some people experience is bites. However, be careful because reaction to bites varies considerably from no reaction to mild (small red bumps) to severe (rash- or hive-like lesions). Also, not all unknown bites turn out to be bed bugs. When you are inspecting for bed bugs, also look for cast skins (empty shells of insects). You may also find dark (not red) spots. These spots are fecal droppings which are composed of digested blood. They are on sheets, bedding, or other places where bed bugs feed or around their hiding places.

Using Temperature to Kill Bed Bugs

Using Heat
You can use your washing machine and dryer to kill bed bugs that may be infesting clothes. Clothes laundered in hot water and dried in temperatures hotter than 122o F for 20 minutes will kill all stages of bed bugs. This is typically the medium-high setting. You can also sterilize curtains and other fabrics, rugs, shoes, backpacks, stuffed animals, toys, and similar objects by drying them for about 30 minutes (for a full load).

Using Cold
Cold temperatures can kill bed bugs if they are exposed to it long enough and at temperatures that are cold enough. If you place objects into a freezer, at 0o F all stages of bed bugs will be killed when they are left in it for 7 - 10 days.

Photo 2: Mattress encasement (see description below). Courtesy: Protect-a-bed.

It is believed (or hoped) that if you put infested furniture outdoors during winter, that the temperatures are sufficient to kill bed bugs. While you will undoubtedly kill some bed bugs, there is no guarantee that you will kill all of them. It is generally believed that if you expose furniture to 0o F or less for four days or more, that may be sufficient.

Even if you put furniture outdoors at 0o F, consider that the temperature where the bed bugs are hiding may not be as cold as the air temperature. Also, any sun shining on the furniture can raise the temperature in localized areas. Although it may seem cold, the odds of the temperature remaining consistently at 0o F or less for four consecutive days are unlikely.

Although you cannot guarantee that freezing temperatures will kill all of the bed bugs infesting an object, you can use the cold to immobilize any bed bugs that are present until you decide what to do with the object.

Barriers

Mattress Encasements

An encasement is a fabric covering that completely encloses a mattress or box springs. It creates a barrier to prevent bed bugs from infesting or escaping mattresses or box springs. Although the encasement can become infested themselves, the infestation is easier to detect. They are useful when you want to protect a mattress you know is free of bed bugs (it has been heat treated or you have purchased a new mattress). You can also use encasements on infested mattresses and box springs trapping the bed bugs inside them and allowing you to continue to use them as long as they are not ripped or torn. Make sure you buy encasements that are specifically designed for protecting against bed bugs. You can purchase encasements from professional pest control services or retail stores.

Bed Bug Interceptors

Photo 3: Bed bug interceptor. Stephen Kells.

These are small plastic trays with an inner and outer ring. They are intended to be placed under the bed legs. Bed bugs that attempt to climb up from the floor to the bed become trapped in the outer well. Any bed bugs that try to climb down will become trapped in the center well. Bed bug Interceptors not only help to reduce the number of bed bugs that can reach the bed but also acts as a monitoring tool to help determine whether bed bugs are present (if that is an issue). You can purchase Bed bug Interceptors online (type bed bug interceptor into a search engine for sources).

Bug Bombs

One of the first products some people reach for when they know they have bed bugs are bug bombs also known as total release foggers. These products throw insecticide into air of which very little, if any, comes in contact with bed bugs which are hiding in cracks and behind and under objects. Its use will not have any impact on a bed bug infestation. Unfortunately, it is too easy for people to misuse or over use bug bombs which can result in unnecessary pesticide exposure. Bug bombs are also potentially flammable if used incorrectly. 

Marla Spivak (University of Minnesota); Eric Mader and Mace Vaughan (Xerces Society for Invertebrate Conservation); Ned Euliss (USGS).
Excerpted from feature article to appear in upcoming issue of Environmental Science and Technology.

Bee Declines

Colony collapse disorder (CCD), the name for the syndrome causing honey bees to suddenly and mysteriously disappear from their hives--thousands of individual worker bees literally flying off to die--captured public consciousness when it was first named in 2007. Since then, the story of vanishing honey bees has become ubiquitous in popular consciousness--driving everything from ice cream marketing campaigns to plots for The Simpsons. The untold story is that these hive losses are simply a capstone to more than a half-century of more prosaic day-to-day losses that beekeepers already faced from parasites, diseases, poor nutrition, and pesticide poisoning.

The larger story still is that while honey bees are charismatic and important to agriculture, other important bees are also suffering, and in some cases their fates are far worse. These other bees are a subset of the roughly 4,000 species of wild bumble bees (Bombus), leafcutter bees (Megachile), and others that are native to North America. While the honey bee was originally imported from Europe by colonists in the early 17th century, these native bees have evolved with our local ecosystems, and along with honey bees, are valuable crop pollinators.

People want to know why bees are dying and how to help them. This concern provides a good opportunity to more closely examine pollinators and our dependence upon them. Bees are reaching their tipping point because they are expected to perform in an increasingly inhospitable world.

Bee declines can be attributed to three factors:

1. Bees have their own diseases and parasites that weaken and kill them. Sick bees are more susceptible to the effects of poor nutrition and pesticide poisoning, and vice versa.
2. Many flowers, nest sites, and nesting materials are contaminated with pesticides. Bees pick up the insecticides, herbicides and fungicides applied to home gardens and lawns, golf courses, roadsides, and crops. These pesticides, alone and in combination, can be toxic.
3. There are not enough blooming flowers over the length of the growing season in our agricultural and urban landscapes to support bees.

Emerging Responses to Declines in Bee Health

To study CCD and other pollinator health issues, the 2008 Farm Bill approved more than $17 million in funding annually for five years for the U.S. Department of Agriculture (USDA) and for university research grants. The Farm Bill also approved another annual $2.75 million for five years to increase honey bee health inspections. Since the Farm Bill became law this funding has never been fully appropriated.

The 2008 Farm Bill also dictated that current USDA competitive grant programs should include pollinators - honey bees and native bees - as research priorities. As a result, research programs funded by the USDA under the National Institute of Food and Agriculture (NIFA), such as the Specialty Crops Research Initiative (SCRI) and the Agriculture and Food Research Initiative (AFRI), made pollinators a research priority in 2010.

Protection from Pesticides

A factor that can be addressed at multiple levels is the use of pesticides. In particular, while extensive literature exists on the sublethal effects of insecticides on bees in the laboratory, little exists on sublethal effects to colonies under natural conditions. Common insecticides such as neonicotinoids and pyrethroids have been shown to affect learning, foraging activities, and nest site orientation by honey bees at sublethal doses.

Individual farmers and homeowners have the ability to mitigate harm to pollinators through simple changes in application methods such as avoiding treatments around blooming plants or to areas where bees are nesting. Evening spraying when bees are less active is another simple, underutilized way to reduce harm. The best course of action, and the one most accessible to gardeners, for whom insect damage is cosmetic rather than economic, is to eliminate the use of pesticides entirely.

The Need for Habitat

The third major challenge facing bees is a lack of season-long food sources, especially in agricultural landscapes where, if bee-pollinated plants even exist, they typically consist of large monocultures like cranberries, canola, or almonds, which provide only a few weeks of abundant food followed by a season-long dearth. Roughly 360 million hectares, or more than one-third, of the lower 48 states are managed as private cropland, pasture, or rangeland. This makes agriculture the largest land use activity in the country and thus one with the most potential impact on bees.

Specific habitat guidelines for all of these landscapes (rural, urban, roadside) vary across regions. Baseline habitat guidelines encourage the inclusion of at least 3 different plant species that bloom at any given time during the growing season (spring, summer, fall), with more being even better. For planting recommendations, visit: www.xerces.org/pollinator-conservation

Concluding Remarks

Pollinators are receiving more conservation attention today than at any other time in history. Scientists, conservationists, and farmers are working harder than ever - in partnership - to understand how pesticides, diseases, and habitat loss impact pollinator populations. They are also working to understand the most successful strategies for creating landscapes that support the greatest abundance of these important insects.

At the same time, the public and policy-makers are increasingly aware of the problems afflicting bees and the critical role they play in food production and natural systems. But there is no reason to wait for research and policy to mitigate the plight of the bees. Individuals can modify their immediate landscapes to make them healthier for bees, whether that landscape is a public rangeland in Wyoming or a flower box in Brooklyn. It is also possible to reduce agricultural and urban pesticide use to mitigate bee poisonings. We can engage in the sustainable management of honey bees and native bees. Promoting the health of bee pollinators can begin as an individual or local endeavor, but collectively has the far-reaching potential to beautify and benefit our environment in vital and tangible ways.

Editor's note: Imadicloprid we have been talking about is a neonicotinoid.

Karl Foord, UMN Extension Educator

Pollinator Blues - Part II

To approach the problem of creating a bee friendly garden,I first researched the plants that are pollinator friendly and created a table of pollinator friendly plants from the Xerces site (Exhibit 1).

Second, I used the following recommendations from the Urban Bee Garden site as criteria for selecting plants; the goal being to insure that continual bee floral food will be available for the complete growing season.

1. Plant a minimum of three plant species that bloom at any given time during the growing season i.e. spring, summer and fall.

2. Each species of flower should be planted to a minimum patch size of approximately 5 ft. x 5 ft. Patch size is important because smaller patch sizes will often be ignored, even if the plant is quite attractive to the bees.

3. Higher bee diversity and abundance occurs when gardens have a rich assortment of bee plants. It also appears that bees remain longer in a garden if plant diversity is high.

Third, I then took an inventory of my present plants and estimated their flowering periods (shown in yellow on Exhibit 2). Fourth, I considered the areas available for planting shown in my property. Given the patch size and species diversity recommendations, I chose six plants to fortify my local bee garden, as follows: Milkweed (Asclepias), Single flowering Roses (Rosa), Catmint (Nepeta), Russian sage (Perovskia), Cosmos (Cosmos), and Lavender (Lavandula). These plants were chosen for attractiveness to bees and longer flowering periods.

I hope that you will consider increasing the attractiveness of your plantings to bees, if appropriate. Taking an inventory of the flowering periods and bee appeal of the plants that you presently have is a good first step. Then choosing plants from the table to supplement, if necessary, should enable you to increase the appeal of your bee garden.

Jeffrey Hahn, Asst. Extension Entomologist

There is a story making the rounds on the internet these days. It goes like this:

Hi All: A bit of information that you might like to know about. We have friends here in our community and one of their sons is an entomologist (insect expert), and has been telling them that there is an epidemic of bed bugs now occurring in America. Recently I have heard on the news that several stores in NYC have had to close due to bed bug problems, as well as a complete mall in New Jersery.

Photo 1: Bed bug. Jeff Hahn.

He says that since much of our clothing, sheets, towels, etc. now comes from companies outside of America, (sad but true), even the most expensive stores sell foreign clothing from China, Indonesia, etc. The bed bugs are coming in on the clothing as these countries do not consider them a problem. He recommends that if you buy any new clothing, even underwear and socks, sheets, towels, etc. that you bring them into the house and put them in your clothes dryer for at least 20 minutes. The heat will kill them and their eggs. DO NOT PURCHASE CLOTHES AND HANG THEM IN THE CLOSET FIRST. It does not matter what the price range is of the clothing, or if the outfit comes from the most expensive store known in the U.S. They still get shipments from these countries and the bugs can come in a box of scarves or anything else for that matter That is the reason why so many stores, many of them clothing stores have had to shut down in NYC and other places. All you need is to bring one item into the house that has bugs or eggs and you will go to hell and back trying to get rid of them. He travels all over the country as an advisor to many of these stores, as prevention and
after they have the problem.

It is true that we are experiencing a significant increase in bed bug problems that has reached epidemic proportions. It is also true that a few retail stores have had bed bug problems and have had to temporarily close. However the rest of the story is unnecessarily alarmist and untrue.

While some clothing stores have found bed bugs, it is not because they were brought into the store on new clothes but rather they hitchhiked into stores on individuals that entered them. Fortunately, the incidence of bed bugs in clothing stores has been rare and owners have taken steps to prevent and better deal with bed bug problems. Because bed bugs would have a hard time finding a person resting for a period of time in clothing store, it is difficult for them to establish a reproducing colony which greatly reduces the risk of someone accidentally bringing bed bugs homes with them.

The idea that you need to worry about clothes you buy, especially those made in Asia, is an unfounded and false statement. The chances of bed bugs inadvertently hitching a ride in new clothes is extremely remote and there are not any known cases of this actually happening. If this was true, we would be routinely seeing bed bugs associated with clothing stores, instead of rarely.

This letter looks like it was meant to alarm and frighten people. Ignore it and continue to buy new clothes as you normally would. We have enough in things in our lives that gives us stress without unnecessarily adding to the list.

Karl Foord, UMN Extension Educator

Jeff Hahn.

Each fall brings the challenge of not only what tropical plants to keep over the winter, but also how to keep them healthy in the Minnesota winter home environment. Invariably despite all efforts I will provide winter refuge for aphids and mites. It seems like this is the perfect time to use imidacloprid. As a systemic it will control the aphids and has no chance of impacting natural populations of insect predators or pollinators in this environment. However, Imidacloprid will not control spider mites. Why not?

The fact that an effective insecticide will usually not harm a mite seems counter intuitive. After all they are both Arthropods i.e. small creatures with exoskeletons and jointed appendages. Although following this basic pattern, the body structure differences between mites and insects are dramatic. On closer inspection the mite has no antennae, no wings, 4 pairs of legs, an unsegmented abdomen, and simple eyes. Whereas an insect such as a bee will have 3 body parts, 2 compound eyes, 2 antennae, 4 wings, 3 pairs legs, and a

Karl Foord.

segmented abdomen. These physical differences reflect a very ancient common ancestor.

The first arthropod fossils date to the Cambrian @ 555 million years ago (mya). From this common ancestor five groups emerged, 1.Trilobites - extinct, 2. Arachnids (spiders & mites), 3. Centipedes and millipedes, 4. Crustaceans, and 5. Insects. The Arachnids and centipedes are more closely related to each other than to the crustaceans and insects. So a lobster is more closely related to a bee than to a spider. Who would have thought? The oldest arachnid fossil dates to the Silurian period 420 mya, while the oldest insect fossil dates to the early Devonian 407 mya. Sometime in the Cambrian period 542 - 488 mya or Ordovician 488 - 433 mya the insect and arachnid lines diverged. During this time the animals diverged physically as well as metabolically. Imidacloprid capitalizes on the metabolic differences.

Insecticides vary in their mode of action, one of which is to interfere with the nervous system. Imidacloprid mimics the action of acetylcholine (a neurotransmitter). The normal functioning system calls for rapid degradation of acetylcholine to maintain control of neural

Karl Foord.

transmission; a little like an on off switch. Imidacloprid is not degraded by normal enzymatic control and thus leaves the switch on which overexcites the nervous system and removes control from the insect. Imidacloprid is specific for insect nervous tissue and doesn't affect mites or mammals in the same manner.

I plan to drench the soil in the pots containing tropical hibiscus, dwarf olive, dwarf Cavendish banana, Australian tree fern, two palms, and the climbing fig. I'll not drench the dwarf Meyer lemon or the star jasmine as I expect them to flower next year and know that the imidacloprid is persistent and could harm pollinators. I have read that bees are attracted to tropical hibiscus, but I have never observed bees visiting these flowers.

My only regret in bringing in the house plants is that I know they suffer from low light intensity. Wouldn't it be great if we could all afford a winter greenhouse for tropical like the one at the Minnesota Landscape Arboretum?

Download a copy of the geologic time scale and access Jeff Hahn's article on mite control.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Photo 1: Brown marmorated stink bug adult. David R. Lance, USDA APHIS PPQ, Bugwood.org.

Gypsy moth, Japanese beetle, multicolored Asian lady beetle, soybean aphid, emerald ash borer. There is a long list of invasive insect pest species that have entered the U.S. and Minnesota and have caused significant problems to crops, landscape plants, or even just as nuisances. An insect that should be on our radar screen that is present in the U.S. but has not been discovered in Minnesota yet is the brown marmorated stink bug (BMSB), Halyomorpha halys. It was introduced from Asia and was first found in the U.S. in Pennsylvania in 2001. It is now known in most mid-Atlantic states as well as in Oregon.

This is a moderate-sized insect, measuring about ½ - 3/4 inch long. Like other stink bugs, it has a shield-like or triangular shaped body. The BMSB is brown with whitish mottling on its body. There are native stink bugs in Minnesota that are also brown and a similar size. The best way to distinguish between them is BMSB has alternating black and white markings on its abdomen. Also look for black antennae with white bands. The immature BMSB look similar but are smaller and lack wings.

Photo 2: Euschistus sp., a native stink bug species in Minnesota. Jeff Hahn.

BMSB are pests because they feed on fruit, like apples and peaches and vegetables, such as corn, tomatoes, and soybeans. They feed on a wide variety of plants and are also found on many hardwood trees and shrubs and some herbaceous plants, although it is not clear how injurious they are to these plants. This year has seen an explosion in the numbers of this stink bug in many areas were they are already known to occur, causing loss in some crops.

Also watch out for BMSB in the fall as they can be pests by entering homes and other buildings as the weather starts to become cold, much like boxelder bugs and multicolored Asia lady beetles. In addition to their unwanted presence, they also give off a very disagreeable, pungent odor.

It is important to discover this insect as soon as possible when it first arrives in Minnesota so it can be controlled. If you believe you have seen a BMSB, report it to the Minnesota Dept. of Agriculture's 'Arrest the Pest' Hotline at 1-888-545-6684 (toll free). You can also e-mail them at Arrest.the.Pest@state.mn.us.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Photo 1: Boxelder bug. Jeff Hahn.

As the days get shorter and the days and nights get cooler, this is a cue to people that summer is ending and fall is upon us. That is also a sign for insects, signaling them that they need to prepare for winter. For some insects and related arthropods, this means finding sheltered places to overwinter which unfortunately can mean our homes.

Some insects, particularly boxelder bugs, multicolored Asian lady beetles, cluster flies, and hackberry psyllids, will fly to buildings and congregate on the outside, especially on the south and west facing exposures where it is the sunniest. As they find spaces and cracks to get inside, some end up in attics, wall voids, and other spaces (where they remain until a mild winter day or spring) while others find their way into the interior part of homes. Yet other arthropods, such as sowbugs, millipedes, and crickets, don't fly but crawl to buildings and find their way indoors at ground level.

Regardless of which nuisance invader you find in your home, the good news is that they do not reproduce indoors and are essentially harmless to people and property. They are short-lived indoors, although some, like boxelder bugs and multicolored Asian lady beetles, can successfully overwinter and can move into the inside of homes periodically during mild winter days and in spring.

Photo 2: Sowbugs under log. Jeff Hahn.

The best management of nuisance invaders is prevention; take steps to keep these insects and arthropods out of your home to begin with. First, examine the outside of your home for possible entry points that they may use to enter your home. Look particularly around windows, doors, where utility lines enter buildings, and areas of buildings where vertical and horizontal surfaces meet. If you are dealing with flying insects, concentrate your efforts on the south and west facing exposures. If you are dealing with crawling insects, check for mulch, leaves, and other possible debris close to the building that may provide harborage. Removing this will make it more challenging for them to get inside. It isn't possible to insect-proof your home so that nothing can get in, but it is possible to minimize the number of insects and other arthropods that can into your home.

Photo 3: Multicolored Asian lady beetles trapped indoors. Gail Felton.

You can supplement your pest proofing efforts by using an insecticide to treat areas where insects and other arthropods are most likely to enter homes. Treat just as you are starting to notice insects coming indoors. Examples of insecticides that you can use, include products that contain bifenthrin, cyfluthrin, deltamethrin, and permethrin. Be sure that the particular product you wish to use is specifically labeled for use around the exterior of buildings.

Once insects and other arthropods get inside, you do not have many options other than to physically remove them with a vacuum or broom and dust pan.

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Dogwood sawfly defoliation. Chris Bauer.

Dogwood sawflies been found defoliating dogwoods during late August. In all of the reported cases, defoliation was severe and apparently appeared suddenly. However, despite the apparent sudden appearance, these sawflies have a actually been present for weeks but just went unobserved when they first started feeding.

Adults are active any time from late May through July. After the larvae first hatch, they are covered in a whitish material which some entomologists believe helps the sawflies resemble bird droppings, protecting them from predation. The young larvae skeletonize leaves, i.e. feed between the veins. Older larvae consume the entire leaf except for the midrib. As mature larvae, dogwood sawflies are about one inch long. Also, the whitish material comes off, revealing their greenish - yellowish, conspicuously spotted bodies.

When they are done feeding, they wander off looking for places to pupate, preferring rotted

Photo 2: Dogwood sawfly (note white material on body). Chris Bauer.

wood. Dogwood sawflies have also been known to bore into homes to pupate. They remain as pupae through the winter and in the following spring There is one generation of dogwood sawflies each year.

If you find your shrubs are being defoliated now, there is not a lot that you can do as dogwood sawfly feeding is either done or is nearly finished. However, if you did have a problem with them this year, watch for them next year starting in June and treat if they are abundant. There are a variety insecticides than can be used if you catch them while they are small, including insecticidal soap, spinosad, horticultural oil, permethrin, bifenthrin, and other pyrethroids. Safari (dinotefuran) and imidacloprid, both systemics, are also effective but need some time to be taken up by the shrubs.

Jeffrey Hahn, Asst.Extension Entomologist

Photo 1: Woolly oak gall. Brittany Koch.

People have been commonly finding about one inch long fuzzy or woolly looking growths on the leaves of oak trees, especially species in the white oak group. These galls are either reddish or whitish or sometimes both. Despite their appearance, these growths are not disease, but is abnormal plant tissue due to the feeding of the larvae of tiny non-stinging insects called cynipid (sin-IP-id) wasps. These galls are common and like other leaf galls, have very little, if any, impact on tree health, especially if they are vigorous, mature oaks. These galls generally do not become very abundant and their numbers vary from year to year on individual trees. By the time you see leaf galls, it is already too late treat them, just ignore them.

Jeffrey Hahn, Extension Entomologist

The early spring has contributed to an above average number of yellowjackets this summer. Yellowjackets can be found nesting in a variety of different places, depending on the particular species. They range from aerial nests, e.g. hanging from tree limbs or the eaves of homes to subterranean nests, e.g. nesting in old mouse burrows to nesting in various voids in buildings. These nests, especially the cryptic ones, are present all season, but may not be noticed until late summer when the workers are more numerous.

Photo 1: Aerial yellowjacket nest. Jeff Hahn.

If a yellowjacket nest is located in a site away from human traffic and is not a risk for stings, then just ignore it. Yellowjackets are beneficial because of the insects on which they prey. All of the inhabitants of the nest will eventually die in the fall when freezing temperatures arrive. If however, the nest is located somewhere where people could get stung, then the nest should be eliminated. There are some situations where you can eliminate the nest yourself. A professional pest control technician is always an option any time you do not want to deal with a wasp problem.

Nests that are out in the open are fairly easy to deal with. Wait until dark when the wasps are much less active. Use an aerosol can of insecticide, something that is labeled for wasps and hornets (or something similar) and spray into the opening. Check the next day to see how effective the treatment was. If you still see wasps flying, repeat the spray the following evening.

Photo 2: Ground-nesting yellowjacts. Jeff Hahn.

Yellowjackets nesting in the ground are more challenging. You do not see the nest itself but you see an opening in the ground where they yellowjackets fly in and out. It is not unusual to walk by a nest in the ground all summer without knowing it is there. Then one day, the yellowjackets will react to a disturbance, e.g. mowing the lawn, and will come out to vigorously defend their nest. The most effective way to control a subterranean nest is with a dust labeled for ground dwelling insects (e.g. Bonide Eight Garden Dust), although these dust formulations are generally difficult to find. Apply it at the entrance of the nest at night when yellowjackets are less active. Check after a day to see how effective the treatment was and repeat if necessary. Another option is to use a liquid insecticide, pouring into the nest entrance, but this is less effective.

Photo 3: Hidden yellowjacket nest in home. Jeff Hahn.

The most challenging yellowjacket nests are those found inside homes in wall voids, attics, concrete blocks, or similar spaces. You can not see the nest, similar to a subterranean nest, but you can see the workers flying in and out of an opening or crack. These nests are very difficult for a homeowner to control on their own. A dust labeled for use in homes is the most effective or a foam formulation, but unfortunately these products are generally not available to the general public. A liquid aerosol, while readily available, is generally not effective. Sometimes an aerosol spray can cause the yellowjackets to look for another way out, which often leads them to the inside of the home. Also, don't seal the nest opening until you know all of the yellowjackets are dead as you can cause the same reaction. The best method to control hidden nests in buildings is to have a professional pest control company treat the nest.

Photo 4: Close up of photo 3. Jeff Hahn.

Remember that yellowjackets are annual nests, i.e. the old queen and the workers only live until the weather gets below freezing, then they die. If you are dealing with a yellowjacket nest late in the season, it might be easiest to wait until the cold temperatures kill them. Nest are also not reused the following spring.

Dr. Vera Krischik, Department of Entomology, University of Minnesota

Native plants used in restoration for wildlife and food plants from apples to zucchini require pollinators. Bees and other beneficial insects offer valuable ecosystem services in both natural and managed agriculture ecosystems, so it is essential to protect them. Pollinators and beneficial insects are experiencing serious decline due to insecticide use, lack of nutritionally rich native plants for pollen and nectar, and lack of habitat. Continued loss of pollinators will have an impact on the natural resources and the economy. This issue has been addressed by the Xerces Society, National Research Council Report, the Congressional Research Report, testimony by the National Academy of Sciences to the US Congress, and the media in newspapers and television programs.

Systemic neonicotinyl insecticides used on landscape plants and crops are considered as a major factor in pollinator decline. After the 1998 ban in France of the systemic seed treatment Gaucho (active ingredient, imidacloprid), French researchers found that imidacloprid is translocated from coated seeds at planting thru the growing plant to nectar and pollen in flowers. In May 2008 a large number of bees died in Germany and the government banned the use of 5 neonicotinyl insecticides, including imidacloprid and clothianidin. A similar event was document in April 2010 by bee researchers at Purdue University. However, in the US use of these 5 neonicotinyl insecticides is very common in greenhouse, landscape, and crops. Almost all of the seed and furrow insecticide applications to corn, canola, soybean, and potato use neonicotinyl insecticides. Native plants grown in greenhouses and transplanted outside may contain high levels of imidacloprid which may kill pollinators.

Research in Vera Krischik's lab in the Department of Entomology at the University of Minnesota demonstrated that nectar and pollen from greenhouse plants treated with soil applications of imidacloprid contained significantly higher amounts of imidacloprid and its metabolites, than from a Gaucho-seed treatment. The label of Gaucho states that 0.375 mg AI for corn and 0.11 mg AI of for canola of imidacloprid should be applied. The greenhouse rate used on perennial landscape plants states that 300 mg AI/ 3gallon pot with 1 plant can be used. This is an 800 times higher rate for corn and 2700 times higher rate for canola. Consequently, greenhouse and urban landscapes use higher concentrations of imidacloprid, which are often reapplied and used at peak flowering, which results in higher concentration being translocated directly to flowers. Consequently, these levels have great potential to alter behavior or kill pollinators and beneficial insects more than the seed treatment Gaucho where most of the research has been done.

Our research on greenhouse rates of imidacloprid showed that the amount of imidacloprid found in nectar of 2 flowering plants was 20 ppb to 41 ppb from a single soil application compared to 1.9 ppb imidacloprid in sunflower nectar and 0.6 to 0.8 ppb in canola nectar from a seed treatment. For buckwheat and milkweed landscape plants, a label rate of soil applied imidacloprid (Marathon 1%G) was translocated to buckwheat nectar at 16 ppb (Krischik et al. 2007) and milkweed at 41 ppb/flower (Krischik et al. 2010). These concentration of caused high mortality of beneficial insects, such as lady beetles, lacewings, and a small parasitic wasp (Smith and Krischik 1990, Rogers et al. 2007, Krischik et al. 2007, Krischik et. al 2010).

There are multiple ways that plants in urban landscapes can contain imidacloprid -contaminated nectar, since it is commonly applied in the landscape for many pests (Krischik and Davidson 2004) and many greenhouse plants are treated with prior to sale and transplanting. Imidacloprid may persist in nectar for a long time, since soil applications were effective against foliar pests for 1 to 2 years in containers (Szczepaniec and Raupp 2007, Gupta and Krischik 2007, Tenczar and Krischik 2007) and landscape trees (Cowles et al. 2006, Frank et al. 2007, Tenczar and Krischik, 2007). Injections of concentrated volumes of imidacloprid (Imicide, Pointer) applied to trees trunks and roots were effective for 12 months for ash (McCullough et al. 2003) and linden (Johnson and Williamson 2007). A soil application of imidacloprid to Eucalyptus tree resulted in 500 ppb in nectar and pollen, which will kill any insect feeding on nectar and pollen. Tree injections of imidacloprid at flowering are cause for concern, since linden flowers are a good source of nectar and pollen for bees, butterflies, and other beneficial insects.

Practice IPM and only use insecticides if you actually witness an insect and associated problem. Think kindly and widely of the need to conserve pollinators and beneficial insects. Apple, cranberrie, blueberries, almond, citrus and 45% of our food plants need pollinators.

Jeffrey Hahn, Asst. UMN Extension Entomologist

Some people are finding field ants nesting in their lawns. Field ants are about 1/4 inch long and black (some species are red and black). Their nests are slightly raised and mound-like and can cover a fairly large area in the ground, up to two feet in diameter. It is not uncommon for people to confuse field ants with carpenter ants. Although these two ants are somewhat similar in size and color, carpenter ants do not nest in the soil. The prefer to nest in cavities in rotting wood or in voids found in buildings. Field ants are most active during the day while carpenter ants are most active at dusk, dawn, and during the night. Because of the mounds created by field ants, some people assume these ants are fire ants. Fire ants are about 1/8th inch long or a little larger. They only occur in the southeastern area of the U.S.; the closest fire ants to Minnesota are in southern Tennessee. Minnesota winters are too cold for fire ants to survive.

Photo 1: Field ant nest. Unknown.

Unlike cornfield ants which are found in bare or thinning areas of lawns, field ant nests are found in healthy, vigorously growing turf. Despite the appearance of the excavated soil on top of the grass, field ant nests typically do not cause any lasting damage to the grass (just rake the soil periodically to prevent it from mounding up). Field ant activity may also make the turf look like it is being undermined from all of the tunneling but this is not likely - a very large nest would need to be present to cause that kind of damage. However, these nests can cause problems when mowing. The blades can become dulled when they strike the mound. Field ants can also be an issue because they can bite, especially when their nest is disturbed.

It may not always be necessary to treat field ants in your lawn. If the nest is not intrusive in its appearance or cause problems in the maintenance or enjoyment of your grass, then just ignore it. If the nest is troublesome, then your best bet is treat it with a granular insecticide labeled for ants found in turf (follow all label direction carefully). Some people want to try a non-chemical method and will pour hot water on the nest to kill it. However, this is not effective; at best you might get the ants to move to another area of the lawn. Others will try much more dangerous tactics like trying to burn and destroy the nest with gasoline or lighter fluid. Not only does this not destroy the nest but you risk causing injury to yourself and damage to your property in the process.

Jeffrey Hahn, UMN Extension Entomologist

Photo 1: Typical springtail. Brenda Postels.

The rainy weather that much of Minnesota has experienced this year has lead to increased numbers of springtails in and around homes and other buildings. Springtails are very small, between 1/16th - 1/8th inch long. They are usually slender, elongate insects (there is a group of springtails that is round and stout) with moderate length antennae. Most springtails are dark-colored, brown, grey or black although some species are also white, and some are even iridescent and brightly colored

Springtails are wingless and do not fly but they can jump. Unlike grasshoppers, crickets, and other insects that use large back legs for jumping, a springtail uses a forked appendage called a furcula (located underneath the abdomen) to propel itself. When not in use, a furcula is tucked up under the body, set like a mouse trap. When it is released, it extends down rapidly sending the springtail forward. A springtail can jump many times its body length.

Despite their small size, springtails can occur in tremendously large numbers and are one of the most abundant insects. One source estimates you would find millions of springtails in one hectare (about 2.5 acres) of land. They are associated with damp conditions and are found in soil, leaf litter, lichen, under bark, decaying plant matter, and other areas of high moisture. They feed on fungi, pollen, algae, or decaying organic matter.

They are occur indoors for several reasons. They can be found in the soil of overwatered houseplants and sometimes adjacent areas. They also occur in damp areas with high moisture, e.g. around plumbing leaks and damp basements. They can also move in large numbers indoors from the outside when moist conditions exit around the home. Springtails can vary in abundance indoors from just a handful to very large numbers. Fortunately, however many you find, they are harmless to people and property and are just nuisances.

Photo 1: Typical springtail. Jeff Hahn.

If you are finding just a small number of springtails occasionally, just ignore them or physically remove them by hand or with vacuum. However, if you are seeing persistent number of springtails they are associated with a moisture problem. The best management is to dry out these areas with a fan or dehumidifier as springtails do not tolerate dry conditions. Also make any structural changes to correct the moisture problem.

If springtails are migrating in from the outside, check around the house for moisture problems. This could include rainspouts that do not carry the water far enough away from the foundation, landscapes that slope towards buildings, or excessive irrigation. It could even be a moisture problem with the roof. Correcting existing moisture conditions will help decrease springtails. As we receive less rainfall, the number of springtails will also naturally lessen.

Although it may be tempting to spray a springtail problem with an insecticide, the products available are not very effective against them. Moisture control is the most effective strategy.

Jeffrey Hahn, UMN Extension Entomologist

Photo 1: Aedes mosquito. Jeff Hahn.

With the rains that have fallen on most of Minnesota recently, you can expect the number of mosquitoes to significantly increase. However, keeping away from these blood-lusting insects is easier said than done. The bites are bad enough but we also have to worry about mosquito transmitted diseases, especially West Nile virus. There are certain precautions you can take to protect yourself when you are in mosquito-infested areas. You can minimize your exposure by avoiding times when mosquito activity is the highest, i.e. dawn and dusk and also wear long-sleeved shirts and long pants.

However, the best method for protecting yourself from mosquito bites is using a repellent. The Centers for Disease Control and Prevention (CDC) recommends several repellents that you apply to your skin and clothes for mosquito control. The best overall repellent has traditionally been DEET (N,N-diethyl-m-toluamide). DEET has been available to the public since 1956 and has been consistently very effective. The CDC also recommends picaridin, considered a conventional repellent, and oil of lemon eucalyptus and IR3535, considered to be biopesticide repellents, derived from natural products.

You can also consider using 0.5% permethrin on clothing, shoes, netting, tents, and other camping gear. This insecticide will kill mosquitoes on contact. However, unlike repellents, don't apply permethrin to your skin.

The U.S. Environmental Protection Agency (EPA) has a web page that allows you to find a repellent that is appropriate for your use. You can enter information on whether you want to use this repellent for mosquitoes or ticks, how long you want the repellent to be effective, and if you are looking for a particular active ingredient.

Jeffrey Hahn, UMN Extension Entomologist

There have been a number of reports of meal moths in homes recently. When at rest, the

Photo 1: Meal moth. Unknown.

forewings of this moth have a dark reddish brown band across the top and bottom of the wings while there is an olive or yellowish green band, outlined by wavy white lines in the center. They have a wingspan of about 3/4 - 1 inch. Their abdomen is typically curved up at a 90o angle when at rest.

Meal moths are not as common as Indianmeal moths, although they both feed on dried food products. Meal moths are known to feed on flour and grain products, seeds, and hay especially when they are damp. These moths are generally not common in homes but are more typically found in mills, barns, and warehouses.

If you do find meal moths in your home, the best control is to find the source of the infestation and remove it. Look where you store dried food products. Don't forget about places where grain and flour products, bird seed and other types of seeds, and dried pet food may have been spilled and forgotten about. Start looking where you most commonly find the moths; this is probably close to where the infestation is. Because meal moths do not generally occur in large numbers, it will be more challenging to find the infestation and will probably require some detective to discover the source of the problem.

Jeffrey Hahn, UMN Extension Entomologist

Photo 1: Cutworm damage on potatoes. Sharon Smith.

Cutworms have been a very common insect problem in many home gardens this year. They have also been commonly reported in Wisconsin and Iowa as well. Most of the cutworms that occur in Minnesota overwinter as large larvae. It has been speculated that the heavy snow cover we experienced this spring increased the survival of the overwintering cutworms. That coupled with the early spring allowed them to occur early in the season. There are some non-native cutworms, e.g. black cutworms, that move up to Minnesota from the south, but they did not appear to have been as damaging this year.

Cutworms hide during the day in the soil near the plants, then feed on plant stems at night. Their damage is most severe right away in spring when plant stems are more tender but not a problem later in the summer. Unfortunately, it's too late to manage cutworms any longer this year. That cutworms were very common this year does not necessarily mean that they will be numerous next spring. There are too many factors that influence cutworm numbers to make a prediction now for 2011. Regardless of how numerous they will be next spring, if you have had an issue with them this year, be on the watch for them in 2011. For more information, see Cutworms in Home Gardens.

Michelle Grabowski, UMN Extension Educator and Jeff Hahn, UMN Extension Entomologist

Photo 1: Ash tree defoliated by ash anthracnose Photo by J. O'Brien USDA Forest Service, Bugwood.org.

With the discovery of emerald ash borer (EAB) in Minnesota in 2009, many homeowners are keeping a close eye on the ash trees on their property. This has resulted in a great deal of concern as many ash trees began to drop their newly formed leaves early this spring. In most cases, however, the cause of this early leaf drop was a common fungal disease known as ash anthracnose.

Emerald Ash Borer

Photo 2: Thin canopy of an EAB infested tree Photo by Jeff Hahn, UMN Extension.

If a tree is suffering from infestation with EAB, the tree's canopy will appear thin, with few to no leaves. Eventually dead branches will be noticed within the tree. Cracks and D shaped exit holes can be found in the bark of infested trunks, and woodpeckers may be noticed frequently visiting infested trees to feed on EAB larvae. The emerald ash borer itself is a slender, ½ inch long, iridescent green beetle. It is active anytime from late May into August.

Ash Anthracnose

In contrast, trees infected with ash anthracnose will have dark brown to black water soaked blotches on leaves and young shoots. These leaves are often distorted and curled around the infected area of the leaf. Infection on petioles and young shoots can result in leaf drop. In some years, leaf drop can be quite severe, resulting in almost complete loss of the first flush of leaves. Infection is often most severe in the lower and inner branches of the tree, where high humidity favors fungal growth. Ash anthracnose is very common in cool wet spring weather, but does not persist in warm dry summer weather.

Help Diagnosing the Problem

Concerned homeowners have many resources available to help them determine which problem is occurring in their ash tree. What's wrong with my ash? Is an online diagnostic tool that helps gardeners diagnose ash problems through a series of simple questions about what symptoms they are seeing. Gardeners should also visit the UMN Extension EAB resource webpage. This page includes many useful tools including a step by step guide to determine if EAB is a possibility in your tree, a publication on insects that may be confused with emerald ash borer, and maps showing where EAB has been found in MN. Those without internet access can call Forest Resources Extension at 612-624-3020 for further assistance.

What is Ash Anthracnose?

Photo 3: Leaf symptoms of ash anthracnose Photo by M.Grabowski UMN Extension.

Ash anthracnose is caused by the fungus Discula fraxinea, and is a common problem on Minnesota ash trees early in the growing season. Whereas Emerald Ash Borer is a serious threat to ash trees, ash anthracnose is closer in severity to a common cold. It's not pretty, it can be stressful to the tree, but it is rarely life threatening.

The ash anthracnose fungus can infect most species of ash trees (Fraxinus spp.). In the Great Lakes states, green ash (F. pennsylvanica) is often most severely infected. The ash anthracnose fungus overwinters in last year's infected leaves and twigs. New fungal spores are produced in early spring in these old infections. This coincides with the opening of tree buds and the emergence of new leaves and shoots. These young undeveloped plant parts are highly susceptible to the ash anthracnose fungus. If cool wet weather persists, ash anthracnose can be quite severe.

The good news is that mature ash leaves are relatively resistant to the ash anthracnose fungus (although infection can occasionally be seen associated with insect feeding or other wounds). As the weather turns warm and dry and tree leaves mature, ash anthracnose is no longer able to spread rapidly throughout the tree canopy. Trees that lost their first flush of leaves, replace them. By midsummer, symptoms of the disease are often difficult to find.

What to Do About Ash Anthracnose?
Ash anthracnose is considered a minor stress to the health of a tree. A mature vigorously growing tree can tolerate complete leaf loss for 2-5 years. Reducing other stresses on the ash tree throughout the growing season can help the tree recover. Simple activities like watering trees during periods of drought, mulching the soil at the base of the tree to reduce competition with turf grass, and avoiding wounding trees with lawn equipment will help the tree recover its strength. Raking up and removing infected leaves at the end of the growing season will help to reduce the amount of fungi that survive from one season to the next, although some fungi often survive in infections within the tree canopy.

Although there are fungicides that will prevent ash anthracnose, it is too late this year for fungicide applications to be effective. Fungicides must be applied early in the growing season to protect young emerging leaves and shoots. Homeowners should not apply fungicides to mature shade trees. The spray equipment available to homeowners will not provide effective coverage in a mature tree, and serious safety risks can occur to homeowners that attempt fungicide application with inappropriate equipment. Fungicide applications are only recommended in trees that have suffered severe leaf loss due to ash anthracnose several years in a row. In this situation a tree care company with a certified pesticide applicator (licensed by the MN Department of Agriculture) should be contracted to safely apply the fungicide at the appropriate time of year.

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Eastern tent caterpillars. Amy Freundschuh.

Eastern tent caterpillars have been common in many areas of Minnesota this spring. This insect is easy to identify because it constructs a silken web in the fork of branches. They attack a variety of hardwood trees, especially fruit trees, including apple, crab apple, chokecherry, cherry. These caterpillars are bluish black with yellow and a white stripe running the length of the top of its body. They are also mostly smooth except for a series of hairs sticking out along the side of their bodies. They are two inches when fully grown.

Eastern tent caterpillars normally emerge late April to early May. This year they emerged several weeks early because of the unseasonably warm weather we experienced in March and April. As a result, most, if not all of the caterpillars are fully grown and finished feeding.

The best time to treat eastern tent caterpillars is when they are half full grown length or less, i.e. no more than one inch long. An easy non-chemical method to manage eastern tent caterpillars is to wait until evening or rainy days when the caterpillars are in their webbing, then pull it out along with the caterpillars. Then destroy the insects by bagging, burning, or burying them. Insecticides are an option. Because fruit trees are typically flowering when eastern caterpillars are active, use a low impact insecticide, such as Bacillus thuringiensis, spinosad, or insecticidal soap. If caterpillars are fully grown, then just ignore them.

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Emerald ash borer adult. Jeff Hahn.

A publication entitled A Guide for Homeowners on Pesticide Selection, Use, Safety, and Environmental Protection is now available. This fact sheet was written by the Minnesota Dept. of Agriculture with help from the University of Minnesota Extension and Dept. of Natural Resources. It discusses factors to consider before using an insecticide, insecticide treatment options, recommendations to protect water quality, information on insecticide labels, and how to measure trees.

A clarification should be made regarding the timing of insecticides. The included chart is generally true but it should be noted that imidacloprid should be treated in spring about 4 - 6 weeks before EAB is expected to emerge, i.e. late May or early June or the previous fall. We are at the end of the time for treatment with imidacloprid. However, the use of Tree age (emamectin benzoate) can still be used until late May to early June.

You can find this publication at the Minnesota Dept. of Agriculture web site.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

With the early spring we have been experiencing this year, ticks have also been active sooner than normal. The two most common ticks we encounter are the American dog tick (also known as wood tick) and the blacklegged tick (formerly called deer tick). Both of these ticks are found in the underbrush of hardwood forests and adjacent open grassy fields

Both are annoyances because they bite people and our pets as they seek blood meals. However, blacklegged ticks are particularly a pest because of their ability to vector diseases. The most common disease they can transmit in Minnesota is Lyme disease (1,050 cases in 2008). Lyme disease is most common in central and eastern Minnesota. Blacklegged ticks are also known to vector human anaplasmosis (278 cases in 2008), babesiosis (24 cases in 2007), and Powassan virus (2 cases ever reported, both in Cass county).

Photo 1: Blacklegged tick close-up. Jeff Hahn.

There are certain conditions that must occur for a blacklegged tick to successfully transmit a disease to you. First, it must be attached and biting you; if it is just crawling on you, it can not transmit disease to you. Second, if it is attached to you, it must be biting long enough. For Lyme disease, the blacklegged tick must be biting for at least 24 - 48 hours; for human anaplasmosis it needs to be biting for 12 - 24 hours. So if you go out into the woods in the morning and find a blacklegged tick biting you in the afternoon, it is doubtful that it has been attached long enough to transmit Lyme disease or human anaplasmosis.

Up to 30 days after contracting Lyme disease, most people (70 - 80%) experience a red circular rash. They may also experience fever, chills, headache, muscle and joint pain, and fatigue. If left untreated, these symptoms can progress into additional rashes, fever, arthritis, muscle pains, irregular heartbeats, stiff neck, and persistent fatigue. If Lyme disease continues to progress, symptoms that may be experienced weeks or months after the onset of illness can include swelling in joints, like knees, continued persistent fatigue, and nervous system problems.

If you suspect you may have contracted Lyme disease or another tick-borne disease, see your doctor. For information on other tick-borne diseases, go to Tick-borne Diseases in Minnesota.

Prevention is the best method to avoid ticks. Stay on trails when possible. Wear protective clothes, such as long pants and long sleeve shirts (tuck pants into socks for additional protection). Use repellents to maximize your protection. Apply DEET on clothes or skin. Use permethrin just on clothes. Permethrin is effective for several wearings and will be effective even if clothing is washed. It is not necessary to saturate clothing or skin with repellent, just apply enough to covered the desired.
When returning from a known tick area, be sure to check yourself for ticks. Promptly remove any and save for identification. For more information on ticks, see Ticks and Their Control.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Photo 1: Recently hatched forest tent caterpillar.Jeff Hahn.

We are experiencing a noticeably early spring. Consequently this has caused insects to become active earlier than normal. During April, insects such as forest tent caterpillar, European pine sawfly, and pine spittlebug were already active, about 3 - 4 weeks ahead of schedule. Undoubtedly, many garden insects are also active as well. That is not to say all of individuals of a species have become active, but at certain sites they have.

If you are anticipating a particular insect problem for mid May, look now, it probably is already present. If you are looking for an insect that normally comes out in early May, it probably is already is active. Inspect your garden and landscape now for potential insect pests.

Dan Miller, Plant Health Specialist, University of Minnesota Landscape Arboretum

Photo: Japanese Beetle. Forestry Images. Russ Ottens, University of Georgia.

The Japanese beetle (Popillia japonica) was first detected in the United States in New Jersey in 1916 and has spread throughout most states east of the Mississippi and to parts of Arkansas, Missouri, Kansas, Oklahoma, Iowa, and Minnesota west of the Mississippi. In Minnesota, the beetles were first detected in 1968. Trapping programs conducted by the Minnesota Department of Agriculture (MDA) showed low but consistent numbers from 1991 to 1998. Trapping data in 1999 and 2000 showed a dramatic increase in Japanese beetles with the highest counts occurring in Washington, Ramsey, Hennepin, Dakota, and Carver counties. After trapping in 2002, the MDA concluded that the beetle was too widespread to be eradicated. The beetle was then deregulated and budget cuts shifted the direction of the program so the statewide trapping program was discontinued.

Arboretum exhibit demonstrates integrated control of Japanese Beetles

In recent years, Japanese beetle infestations have become more noticeable in the metro region with many reported cases of damage to golf courses from the white grub larvae feeding on grass roots and damage to ornamentals shrubs and trees (especially roses, grapes, and lindens) from adult beetles. It is apparent that awareness of the pest is growing; however many home gardeners are not experienced or knowledgeable regarding integrated control strategies for the pest. In 2009, the Minnesota Landscape Arboretum obtained a grant from the North Central Integrated Pest Management Center to create an exhibit at the Arboretum to provide updated, relevant IPM information to the public on environmentally safe ways to control the adults and larvae of the Japanese beetle. The display featured a sign located in the center of a plot of turfgrass and roses with general IPM information, a take-home brochure with more detailed information, and a terrarium so visitors could observe the beetles while they were feeding on plants.

Determining the distribution of Japanese Beetle in Minnesota

A secondary part of the grant involved a survey to determine the current statewide distribution of the beetle. In August 2009, an electronic survey was sent to over 300 golf course superintendents via the Minnesota Golf Course Superintendents Association. In October a second electronic survey was sent to nurseries throughout the state via the Minnesota Nursery and Landscape Association. These surveys provided links for respondents to use in properly identifying the beetle. The survey also asked if beetles or grubs had been observed on their golf course or nursery, when they were first observed, the damage levels, and the control strategies employed. Additionally, over 40 University of Minnesota Extension Educators and Master Gardeners across the state were contacted by phone and asked if they had heard of infestations in their areas. Based on previous trapping surveys by the Minnesota Department of Agriculture and our 2009 consensus surveys, it is apparent that the beetles are primarily located in the seven county metro area and southeast toward Rochester and west toward Mankato (Figure 1). Future IPM control efforts should be focused in these areas.

Even though Japanese beetles have been present in the metro area for several years, they were not observed at the Arboretum until 2007. To get a better understanding of the encroachment of Japanese beetles to the Arboretum, a trapping study was initiated in 2009. Twenty traps were set on golf courses and parks in an approximately 10 mile radius round the Arboretum and compared to traps on the Arboretum grounds. Traps were set in each location once a week, left for 24 hours, retrieved, and beetles were counted. Trapping started on July 17th and continued for ten weeks until September 16th. The most remarkable outcome of this trapping project was the noticeable difference between trap counts on golf courses east of the Arboretum and golf courses west of the Arboretum. The average number of beetles per trap for the four golf courses east of the Arboretum was 483.0 while the average number for the two eastern courses was only 2.6. The average number of beetles for the Arboretum's traps was 5.7. Several golf course superintendents indicated that 2009 was either the first year or the second year that they were aware of the beetle's presence. It appears that the Japanese beetle populations are increasing and are continuing to advance further west. 

Figure 1. Status of the Japanese Beetle in Minnesota in 2009 (PDF available: JapaneseBeetleMN2009V3.pdf)

Methods for decreasing potential damage from Japanese Beetles

Homeowners and golf course superintendents in the metro and southeastern region of Minnesota can decrease potential damage to their ornamentals and turfgrass by scouting and early detection.

Golf courses (and other turf managers) should concentrate their control efforts on the grubs if turf damage is considerable. Imidacloprid and Acelpryn (a reduced-risk insecticide) have proven to be effective.

Homeowners can control small infestations of adult beetles by picking them off the plants and dropping them into soapy water or rubbing alcohol. Pheromone traps are not recommended as beetles may miss the trap and land on nearby landscape plants, causing damage.

If damage is beyond tolerable levels, conventional insecticides may become necessary. Imidacloprid and residual pesticides like pyrethroids are effective for adults but should only be used where infestations are found and not used as preventative treatments.

Homeowner's can treat grub damage using biorational control with products containing halofenozide an insect growth regulator or with beneficial nematodes. It is necessary to confirm that turf damage is caused by white grubs and not by other turf diseases before implementing control methods.

Detection of Japanese Beetles in new counties

If beetles are found in counties not marked on the map in Figure 1, please let us know by sending specimens including capture location and date to Jeff Hahn at Department of Entomology 236 Hodson Hall, 1980 Folwell Ave., St. Paul, MN 55108 or send digital images to hahnx002@umn.edu.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Photo 1: Elm gall midge larvae on sidewalk. Unknown.

Large numbers of very small, about 1/16th inch long, pinkish worms were found during mid April under elm trees. Looking like grains of rice, these 'worms' are actually a type of fly known as a gall midge. It is not clear what species is present but they appear to attack the developing samuras (winged seeds) in early spring. Later in the spring (sometime in April to early May), the mature larvae drop to the ground where they remain until the next spring. The galls are harmless to the tree and no control is necessary. The larvae can be a nuisance when they fall on driveways or sidewalks. The only necessary step is sweep them off. This is a short lived problem that will go away on their own.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Photo 1: Declining due to EAB. Jeffrey Hahn.

With the discovery of emerald ash borer (EAB) in Minnesota last year, people with ash on their property are concerned about possible attacks from EAB and what they should do, if anything, to protect their trees. Insecticides are an effective method to protect your ash from EAB but does this mean this is what you should do? There are a number of factors that people should consider when weighing their options.

The first factor you should consider is how far are you from a known EAB infestation. The general guideline is that the highest risk from EAB occurs when you are within 10 -15 miles from a known infestation. Right now, EAB is only confirmed in St. Paul and Minneapolis. This means that essentially all of the Twin Cites metropolitan area is at a high risk. However, if you are in Minnesota outside of this 10 - 15 mile radius, the risk from this exotic borer, while not zero, is much smaller and treating your ash for EAB is not suggested.

You should also ask yourself what condition is your ash in. When trees are healthy or at least mostly healthy, i.e. dieback or decline in the canopy does not exceed 40% - 50%, they are a possible candidate for treatment. If the trees are in poor health and the canopy shows over 50% dieback or decline, it's not worth saving the tree. Also, when a tree has suffered significant girdling damage from borers, its ability to move insecticide through the tree to protect it is greatly reduced.

How valuable is your ash to you? Does it provide shade for your house; is it an important part of the aesthetics of your yard; does it has sentimental value? Or is it just another tree in your yard and it wouldn't be missed? The more valuable your ash is, the more likely you will try to save it.

You should balance these factors with the cost of treating trees versus the cost of removing and/or replacing trees. When considering insecticides, remember that the cost will vary according to how large the tree is, how many trees you are treating, what insecticide is being used, and the fees charged by individual companies.

It is very important to remember that once you start using insecticides, it is a long term commitment and you need to continue to treat your ash regularly (every 1 - 2 years) for the life of the tree. Ash do not develop any resistance when they are treated, so if you stop using insecticides after a number of years, they are just as vulnerable to EAB as they were before you started to treat them. So while the cost of a removing a large ash may be considered to be expensive by some, it is a one time cost compared to the ongoing, long term price of treating trees.

What is the right action for you to take? There isn't one right answer. What a person may do will depend on their particular circumstances - the right solution for one property owner may not be appropriate for someone else. However, consider the above factors to help you make a decision that is right for you.

Michelle Grabowski, University of Minnesota Extension Educator and Jeff Hahn, University of Minnesota Asst. Extension Entomologist

Photo 1: Hackberry tree with witches brooms. W. Cranshaw, Bugwood.org.

As you look up at the trees this spring, watching for emerging buds or perhaps a returning song bird, you might notice many small clumps of short twigs scattered through the branches of some hackberry trees (Celtis occidentalis). These clumps of twigs are called witches' brooms. Although witches' brooms are present within the trees canopy throughout the year, they are most easily observed in the winter or early spring, before leaves emerge. Hackberry trees growing in open areas, like a yard or along a street, are more likely to have witches' brooms than hackberry trees in a forest. Often one hackberry tree will have many witches' brooms while its near neighbors have none.

Witches' brooms occur when the bud of the tree is injured or infected. Normally, a healthy bud opens to produce one shoot. However, when a bud is damaged or killed, multiple weak shoots may develop from the same point on the branch. Witches' brooms in trees can be caused by a variety of problems. Trees growing alongside roads where salt is applied in the winter may have buds damaged or killed by splashing salt. In some cases, infection of the tree by a fungus, a phytoplasma or even a parasitic plant like mistletoe can cause witches' brooms to form within the tree's canopy.

Photo 2: Witches broom on hackberry tree, up close. W. Cranshaw, Bugwood.org.

The exact cause of hackberry witches' broom remains unknown, although two organisms are consistently found within these twig clusters. The first is an eriophyid mite, Eriophes celtis. Eriophyid mites are tiny, measuring no more than 0.5 mm (1/50th inch) long. Even with magnification, people are unlikely to see these mites. Little is known about their life cycle. We do know that eggs are laid in May and mites cluster on the buds, developing until the end of the summer. The second organism is the powdery mildew fungus Podosphaera phytoptophila. The fungus may be seen as a white cobweb like coating growing on the young shoots and leaves within the witches' broom in spring or early summer. Throughout the year tiny brown to black round fungal resting structures can be found on infected buds, but these are best observed with the help of a magnifying glass. How these two pests interact with the hackberry tree is uncertain. One theory suggests that the eriophyid mite causes the witches' broom to form and the powdery mildew fungus takes advantage of the weakened plant and starts an infection secondarily. It is clear that hackberry witches' broom causes little damage to the health of the tree. Trees with numerous witches' brooms have been found to grow vigorously for years.

Photo 3: Several hackberry witches brooms, up close. Jeff Hahn. 

Since the true cause of the witches' broom remains uncertain, there is no known method to prevent or to control the problem. Gardeners who are concerned about the affect of the witches' brooms on the ornamental value of the tree can prune off severely infected branches. In most cases however, hackberry witches' broom is only an aesthetic problem in the winter months. The flush of new leaves soon to be produced will hide the witches' brooms, leaving only a beautiful green canopy to be seen by the casual observer.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

An interesting sample was received from northwest Minnesota in March during a week when the weather was unseasonably warm. More than 20 insects were found on the carpeting in a couple of rooms in a Senior citizens' home. They were worried that they would be damaging and spread to other areas of the building.

The insects in question are a species of rove beetle. Rove beetles are very common insects, although the are often overlooked by people. Most are small, 1/16th - 1/8th long and are conspicuous because of the short wing covers they possess which leaves much of the abdomen exposed. Rove beetles are often associated with dead animals and dung as well as on the ground under stones and other debris. They are predaceous on other insects.

Photo 1: Rove beetles. Howard Person.

Fortunately, rove beetles are not harmful to people or our property. They do not reproduce indoors and are just a temporary nuisance. It is likely that these particular beetles overwintered near the building and wandered indoors when warm temperatures arrived. The use of a vacuum or some other type of physical removal is the only necessary control.

Minnesota Department of Agriculture news release

The Minnesota Department of Agriculture (MDA) confirmed on Thursday February 25 an emerald ash borer infestation in four trees in the Prospect Park East River Road neighborhood of Minneapolis within Tower Hill Park. This infestation is within a mile of the St. Paul neighborhood in which the tree pest was found last year.

Photo 1: Emerald ash borer galleries. Jeffrey Hahn.

The infestation was discovered through an ongoing survey of ash trees in the vicinity of the South St. Anthony Park neighborhood, where EAB was found in May 2009. While this marks the first time emerald ash borer has been found in Minnesota outside Ramsey County, state officials said the discovery was anticipated. Last fall, scientists determined that the St. Paul infestation had been in place for about three years prior to detection. Since the adult beetles can fly up to 2 miles each year, officials expected that the bug had spread into Minneapolis.

There is quarantine for emerald ash borer in place for Ramsey and Hennepin Counties as well as Houston county in the southeast corner of Minnesota that prohibits moving from those counties any items that may be infested with EAB, including ash trees and ash tree limbs, as well as all hardwood firewood. This quarantine remains in effect in 2010.

The Minneapolis Park and Recreation Board's Forestry Division is responsible for planting and maintenance of public trees on Minneapolis city streets and parkland. The Park Board's forestry division has been working with MDA to prepare for the arrival of EAB. Next steps will include removal of infested trees and an intensified survey of all ash trees in the surrounding area.

For more information on emerald ash borer, go to the University of Minnesota Extension's EAB web page

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Although it is cold outside, that does not stop some ants from being active in buildings. A common indoor winter ant is pavement ants. A pavement ant is 1/8 inch long and is reddish brown (it can actually range from light brown to dark brown). If you examine a pavement ant closely, you will see a two-segmented petiole, the 'waist' connecting the abdomen with the thorax. With magnification, you can also see a series of fine grooves etched into their heads as well as a pair of small spines on the back of their thorax.

Photo 1: Pavement ant. Jeffrey Hahn.

Pavement ants typically nest in the soil, usually under objects, such as stones, bricks, sidewalks, and driveways. When they are found during winter, they are nesting in the soil under the concrete slab. When the nest is kept warm from the building's heat, the ants stay active, move through cracks in the concrete and actively forage for food and water. Ironically, many people that see pavement ants during winter do not see them in the summer when the ants are more likely to forage outdoors. Pavement ants prefer to feed on greasy food, including meats, dry pet food, and peanut butter.

If you are having a problem with pavement ants, first see if you can determine where they are coming from. If you find them moving through a crack, e.g. in an expansion joint, you can try to seal it to help keep pavement ants out of your home's interior.

If this isn't possible, the best long-term control is baiting them. Select a bait that is effective for grease feeding ants and place it where you are commonly finding the ants. Don't be surprised if there is an increase in the number of workers that are active around the bait. They will recruit additional foragers to take advantage of the newly discovered food source.

You might be tempted to spray the ants with a household insecticide but the number of foraging workers represents just a small percentage of the total number of ants in the nest. You can't destroy a nest through attrition by killing the workers you see. You can get some relief from their presence but it will only be temporary and the ants will return. Insecticides will also interfere with the ability of the workers to take bait back to the nest. The less bait that is brought into the nest, the less effective it will be in eliminating it. You can also consider hiring a professional pest control service to treat your ants.

If you ignore pavement ants, they will probably start foraging outdoors as warmer weather arrives, and 'disappear' from inside a building.

Keep in mind that not all ants seen during winter are pavement ants. You may also see carpenter ants, Pharaoh ants, yellow ants, and thief ants. Their habits differ as well as their treatment. If you have any doubt as to what kind of ant problem you have, get them identified them by an expert.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Bananas are favorite fruit of many people. Because they are grown only in tropical areas, they need to be imported into Minnesota. Some people have occasionally discovered inadvertent hitchhikers, primarily spiders, that have been accidentally been brought into Minnesota with the bananas. Recently an interesting cockroach was discovered around bananas.

Photo 1: Cuban cockroach. Jeffrey Hahn.

A person in Morris, Minnesota (in the west central part of the state) found an insect around a sink where some bananas had been sitting. The insect was about 3/4 inch long, pale green, with long antennae and fully developed wings. A quick check of the literature revealed that the insect in question was a Cuban cockroach.

A Cuban cockroach gets it name because it was originally collected in Cuba. It is now commonly found in Mexico, Central America, and northern South America. It is only found in the U.S. in Florida. Although a Cuban cockroach is an outdoor species, it likes to enter buildings and other structures. They particularly are attracted to lights. Cuban cockroaches are also commonly brought indoors on bananas.

Because this cockroach species is native to tropical and subtropical areas, it does not survive long in the upper Midwest. In fact, this particular individual died shortly after it was found. A Cuban cockroach should not be considered a pest when it is found in Minnesota. It is short-lived, does not reproduce in homes, and does not cause any damage. If you find one, just consider it a curiosity.