Recently in the Insects Category

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).

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.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

In the fight against bed bugs, one of the challenges is knowing whether these biting insects are present and where they are located in a building. Recent research at Rutgers has developed a monitor that will make it easier to find them. This research was presented at the 2009 Entomological Society of America (ESA) annual meetings held in Indianapolis and has since been widely reported in the media.

This research, conducted by Wan-Tien Tsai and Changlu Wang, found that a monitor could be successfully made from an insulated plastic 1/3 gallon jug filled with about 2 ½ pounds of dry ice pellets. You leave the pour spout partially open to allow CO2to escape which emits CO2 for about 11 hours. The jug is set on top of an upside pet food dish. Put fabric around the outside of the dish to allow bed bugs easy access to the inner part of the dish. You should also coat the inner section of the dish with talcum powder so the bed bugs can not climb back out. This trap costs about $15.

Photo 1: Do-it-yourself bed bug monitor Rutgers Cooperative Extension.

While this monitor has been demonstrated to be effective in detecting bed bugs, some members of the media have misconstrued this technique as a cheap method for controlling bed bugs. This monitor WILL NOT CONTROL AND ELIMINATE bed bugs in your home. Further, there are apparently some reports of pest control services (although none I am aware of in Minnesota) that have been using this monitor incorrectly in bed bug control programs.

Again, these monitors are to be used to determine whether bed bugs are present in your home. People that are suffering unknown bites but have not seen any insects could verify whether bed bugs are present or not with this monitor. For people that have bed bugs treated in their home, this trap can be used to help determine whether any bed bugs still remain.

With that said, there are some drawbacks to this monitor and people should consider carefully whether they wish to use it. First, while the components to build this trap are inexpensive, dry ice may not be easily obtained. People need to exercise caution when handling dry ice. You should never touch dry ice directly or allow it to contact bare skin as this will cause freeze burns. You can not store dry ice, not even in your freezer. You have less than a day to use it before it evaporates.

This monitor is also a potential child hazard. The trap is unsecured and a curious child could open the jug and accidentally touch the dry ice and severely injure themselves. It is even possible that if more dry ice is used than is suggested and the trap is placed in a small room with poor ventilation that the CO2 could be very harmful to people in that room.

This monitor is an advancement in the war on bed bugs but people that are considering whether to make one themselves at home need to understand its safe and use and limitations. For more information on bed bug monitors, including dry ice traps, see the Rutgers Cooperative Extension fact sheet, http://njaes.rutgers.edu/pubs/publication.asp?pid=FS1117

Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Ficus sphinx caterpillar. Janet Moe.

In early December, a Minneapolis garden center found a large caterpillar. Initially, they said it was found amongst some cut flowers the store received from California. They submitted the caterpillar to the Entomology Department. This caterpillar, measuring three inches long, was light green on the lower half of its body and a reddish orange striped pattern on top. After a quick check of the references, it was determined to be a ficus sphinx, (sometime called fig sphinx), Pachylia ficus.

Like the name suggests, the preferred food of this caterpillar is different species of Ficus plants. It has also been reported feeding on mangos. But don't expect to find this insect on the Ficus in your home or office. A ficus sphinx is a tropical and subtropical insect that is found in northern South America, including Uruguay, Brazil, Bolivia, Central America, the West Indies, and occasionally ranging into Florida, southern Arizona and Texas. Of course, it is can be found in other areas of the country when it hitches a ride on Ficus plants that are transported north but this is rare.

The coloration of the caterpillar is quite variable including greenish and brownish forms. Interestingly, when diagonal stripes are present they slope away from the tail which is unusual for sphinx moths. Some individuals undergo a dramatic color change to green with an orange back, like was found, just before it pupates. The characteristic horn or tail that most sphinx caterpillars possess is greatly reduced to just a nub in this species.

Photo 2: Female ficus sphinx moth. Dan Janzen.

The caterpillar pupates on the ground amongst leaf litter and other plant debris. An adult ficus sphinx has orangish brown forewings with a light colored patch near the tips while the hind wings are orangish brown with a black band across the wing along with a black border along the edge. This moth has a wingspan between 4 3/4 - 5 ½ inches.

When the gardening center was called back to notify them of the identification of the caterpillar, they said that after a little more investigation they actually discovered that the insect was not found in cut flowers but on a Ficus which of course made perfect sense.

Bob Mugaas, University of Minnesota Extension Educator
Jeffrey Hahn, Asst. Extension Entomologist

Photo 1: Close up of cottony grass scale. Jeffrey Hahn.

This past year saw a significant increase in the number of reported cases of cottony grass scale (CGS), Eriopeltis festucae, in Minnesota lawns. In 2007, we were only aware of one reported case of cottony grass scale. By 2008, that number had grown to about 6 newly reported cases with the one from 2007 disappearing entirely as there were no signs of infestation in 2008. However, by the end of September in 2009 the number of reported cases that we knew about rose sharply to between 75 and 100. While these were reported cases and not necessarily confirmed infestations, most recognized and described the symptoms, and ultimately the insect, as that shown in our previous article first describing this insect in Minnesota. (See the December 2008 YnG newsletter). Hence, it appears reasonable to assume that most identifications were likely correct.

In order to get a better feel for the scope and range of this insect in Minnesota, it was decided to conduct a survey of those reporting CGS infestations to us. The survey was conducted with SurveyMonkey.com with potential participants notified via email that the survey had been posted followed by a request that they take a few minutes to complete the survey. All respondents and responses were kept anonymous. 

The survey covered a variety of topics ranging from symptoms observed, site conditions where most commonly found as well as cultural and pesticide practices employed to manage and control the pest. Sixteen respondents of about 18 receiving the questionnaire completed the on-line survey. This article summarizes those results as well as provides an update to last year's article concerning CGS In Minnesota. 

While our awareness of this pest was first noted in 2007, one survey respondent reported seeing it in 2006 although we are not certain as to its location. In 2007 and 2008 all of the reported infestations were from around the greater Twin Cities metropolitan area. In the survey, CGS was reported in just two sites in 2007 and only nine sites in 2008. In 2009, reports of CGS infestation had expanded to include many Twin City municipalities as well as reports from border counties in western Wisconsin, Mankato, St. Cloud, Brainerd and Alexandria. There may be other locations as well. However, we only have confirmed documentation from those particular areas. In the survey, CGS was observed at 63 - 78 sites. It is unclear why this dramatic increase of reports occurred. 

We were very interested to learn if CGS was successfully surviving winters. Of the single site in 2006, the 2 properties in 2007, and the 9 lawns in 2008, CGS was observed on all of same properties the following season. Although not reflected by the survey, we are aware of at least one property where CGS has not been found in two years since it was first found in 2007. Still, this suggests that CGS are capable of surviving winters in Minnesota.

Typically, CGS is observed in August or September, although in a few cases it was noticed in June and July. Late summer coincides with when CGS matures into adults and produces egg sacs. These stages are much more conspicuous as a white woolly material surrounds the insect, making them much easier to see in the grass. The life cycle is still not well understood but this species is reported in the literature to overwinter in Maine in the egg stage. That appears to be true in Minnesota.

Photo 2: Typical mower wheel track striping pattern associated with CGS when mowed in one direction. Bob Mugaas.

As was noted last year, the most common symptom associated with CGS is the distinctive mower pattern in which the wheel tracks consistent with those of a commercial riding mower remain green and mostly non-infested. This creates a striped pattern where grass is mowed in only one direction or a checkerboard pattern where grass is mowed in two directions and at right angles to each other. See Pictures 2 and 3. The area below the mowing deck varied from light to very heavy infestations of CGS with the corresponding yellow to tan grass blades associated with their feeding. Only two of sixteen respondents reported an infestation that did not show-up in that same pattern. In one of those instances a walk behind rotary mower was used as opposed to a commercial riding type of mower.

Photo 3: Mower wheel track striping pattern associated with CGS when mowed in two directions perpendicular to each other. Bob Mugaas.

While that sort of mowing pattern suggests that the insects may be being destroyed via a crushing action imparted by the riding mower, it remains uncertain as to whether or not, or how much of that really occurs. Further evidence gleaned from the survey that some type of crushing action is occurring was noted by three of the survey respondents. In one instance, a respondent noted that when the area was rolled using the roller on a lawn aerifier, the lawn improved dramatically within two to three weeks. In another instance, the infested area was rolled with (presumably) something like a sod roller where it was again noted that the lawn recovered 'rather quickly'. In this last case the rolling was done when the cottony, cocoon-like grass scales were present and visible on the grass blades. One respondent noted that by not mowing in the same wheel track pattern each time, thereby destroying another portion of the CGS infestation, recovery of the turfgrass was evidenced by improved green color. See picture 4. 

Photo 4: Comparison of infestation levels in areas associated mower wheel track and not mower wheel track areas. Note lack of infestation in greener, wheel track areas compared to areas in between wheels. Bob Mugaas.

To the best that we can interpret from survey information, all of the rolling/crushing activity would have occurred when the cottony, sac-like structures were clearly evident. While the above observations are very important in helping us better understand the potential vulnerability of CGS, it is hoped that further investigation and observation will help clarify the specific association with mower wheel tracks and the presence or absence of this pest in those specific, rather narrow areas. 

Previous information provided by people encountering this problem indicated that it was primarily found on more highly maintained lawns presumably dominated by Kentucky bluegrass and for the most part receiving full sun exposure. As a follow-up to that anecdotal information, the survey asked respondents to identify the lawn care situations where this pest was being observed. Their choices were as follows:

• Highly maintained lawns (e.g. regularly mowed, fertilized at 3 to 5 pounds of N per 1000 square feet annually, irrigated, kept green throughout the year)

• Moderately maintained lawns (e.g. regularly mowed, fertilized at 2 to 3 pounds of N annually, irrigated as needed to keep lawn basically green but some browning tolerated)

• Low maintenance lawns (e.g. mowed as needed, not irrigated at least with any degree of regularity, fertilized with 1 or 2 pounds of N annually, brown grass associated with summer dormancy is tolerated)

Twelve of the sixteen respondents indicated that this was a pest primarily infesting more highly maintained, Kentucky bluegrass lawns thus lending credence to what others were saying as well as our own observations. Only three indicated a presence on moderately maintained lawns and only one respondent noted CGS presence on a low maintenance lawn. While not asked directly in the survey, personal observation of infested sites along with input from others indicated that this pest is not as attracted to the fine fescue (only two reports) lawn grasses. While their presence was noted on the fine fescues it was in much smaller numbers than that observed on Kentucky bluegrass. In another sighting, it was observed that the creeping bentgrass growing in the same area as Kentucky bluegrass was not infested while the surrounding Kentucky bluegrass was heavily infested. See Picture 5. 

Photo 5: Note non-infested creeping bentgrass compared to surrounding Kentucky bluegrass. Here Peter Fanjul.

From this limited amount of field observation, it would appear that well maintained, predominantly Kentucky bluegrass lawns, are more likely to be infested with CGS than those lawns receiving moderate to low levels of maintenance. With this being a relatively small sample size, further observation and monitoring will help confirm any turfgrass species preferences of this pest. While the level of sunlight received by the infested areas was not specifically asked in the survey, it would generally be assumed that an otherwise healthy, more highly maintained Kentucky bluegrass lawn would be located in an area receiving full to mostly sunlight conditions. However, there are at least two reports, one from the survey and one not, that did observe CGS in partially (tree) shaded areas of the lawn. In light of where this pest appears to occur most frequently, it would appear that its preference would be for actively growing Kentucky bluegrass in mostly sunny areas. However, its occurrence in more shaded situations cannot be ruled out. Again, future monitoring and observation should help clarify site and plant material feeding preferences of CGS.

Another aspect of CGS management that the survey helped assess was whether or not the implementation of any particular cultural practice or change in cultural practice helped improve the turfgrass stand (i.e., symptoms abated and grass color and vigor improved). Ten of sixteen respondents tried making at least one cultural practice change compared to what was previously being done. Those cultural practices asked by the survey included:

1. use of more or less water
2. use of more or less nitrogen
3. mowing heights increased or decreased
4. mowing frequency less often or more often
5. lawn dethatched only, lawn aerified only or, lawn dethatched and aerified.

Four of the ten respondents who indicated the implementation of at least one cultural practice change noted that the lawn improved following those practices during the same growing season. Two respondents reported no improvement. 

There was no clear pattern of practices that seemed to be any more helpful than another. For example, the one respondent who indicated that they 'aerified only' reported improvement in the turfgrass similar to two respondents who utilized four different practices including the use of aerification. Of the two respondents that increased water or chose to mow less often, both indicated seeing no improvement in the turfgrass. A respondent who indicated an increase in N and mowing higher was uncertain as to whether or not the situation had improved. However, that same respondent did indicate that use of Merit alone or with cultural practice changes (presumably those mentioned above) resulted in improvement in the turfgrass stand. When changes in cultural practices were combined with the application of an insecticide, four of six respondents noted an improvement while two noted no improvement. 

While there appears to be a clearer understanding as to this pest's preference for well maintained lawns, it is not as clear as to which cultural practices might be more important in either encouraging or discouraging the establishment of and/or maintaining an existing pest population. Also, there does not seem to be a clear cut pattern of control using pesticides alone or with a particular set of cultural practice changes. For example, of the two respondents who indicated that they reduced water and nitrogen amounts and used an insecticide (Merit), one noted improvement while the other did not. 

Eight people applied insecticides to attempt to manage CGS. Two used Merit and both believed these applications decreased the population of CGS. One applicator also treated his lawn with Talstar (bifenthrin) but did not think it was effective. One respondent used both Merit and Talstar believing that this was effective management. Likewise, one person used Scimitar (lambda cyhalothrin) and thought he gained a reduction of CGS. There was also a single record of acephate although they did not record whether they thought it was effective. Another person used horticultural oil but didn't know whether it was effective. 

It is interesting that the insecticide applications appeared to improve the turf in some cases. Although Merit should be effective, it would not be expected to have an impact on CGS numbers until the following spring. We would not expect any of the residual insecticides (Talstar, Scimitar, horticultural oil) to be effective on adults, although they would be effective against crawlers if you were able to time the application when they were present.

Eight out of nine people that did nothing did not see an improvement in the turf in the same season. There was one respondent that said the turf was looking good again by late October. It will be particularly interesting to observe infested lawns next spring to see whether they have recovered or not. It has been our observation to this point that turf does improve without any lasting injury. With many more properties to examine, this will help us determine if this generally true.

In summary, it is understood by the authors that this survey represents a relatively small number of respondents. Nonetheless, it is an attempt to gather rudimentary yet useful information about CGS presence, habits and control strategies being utilized in Minnesota to manage this pest. It is hoped that our own further observation and monitoring plus valuable input from the lawn care industry will continue to provide an expanding data base on CGS management. From that information, effective IPM strategies can be developed and refined to provide lawn care personnel as well as homeowners with a variety of effective management and control options for CGS.

Jeffrey Hahn, University of Minnesota Asst. Extension Entomologist

Photo (above): Northern mole cricket. Jeff Hahn.

An unusual insect, a northern mole cricket (Neocurtilla hexadactyla), was submitted to the entomology department in August. This insect was found by a homeowner in their yard in North Branch (Chisago county) in east central Minnesota. Northern mole crickets are found throughout the eastern U.S. in low lying moist areas, e.g. along the margins of lakes and streams. They are rarely found in home lawns and are not considered to be a pest in Minnesota.

This brown insect grows up to 1 1/4 - 1 1/3 inches long, has moderate length antennae and short wings that only extend about half way down its abdomen. What is particularly distinctive about this insect is its stout, mole-like front pair of legs which are modified for digging (called fossorial). They have four dactyls (claws) on their tibia which distinguishes them from closely related mole crickets. Despite their ungainly appearance, northern moles crickets are capable of flight, flying at dusk.

They spend essentially their entire life underground where they feed on grass. If a northern mole cricket is exposed, its first reaction is to dig back down into the soil.

They take two years to develop into adults. Females lay eggs in spring in chambers in the soil. The immature nymphs develop slowly and spend the first winter as nymphs. They eventually mature the second year wintering as adults.

A northern mole cricket is a relatively uncommon insect in Minnesota, but even less commonly noticed by people due to its secretive habits. Interestingly, a number of eastern states also reported encountering this insect this summer in instances when they normally do not. It will be interesting to see if this a future trend or if this year was just a good year for northern mole crickets.

Jeff Gillman, Nursery Management Specialist

Different people collect different things. Some like baseball cards, some like shoes, and some like coins. I like books about insects. No, really, I do. Just glancing up from my desk I can count something like 5 field guides, 10 general entomology texts, and a slew of others that fit into categories like insect control, insect taxonomy and insect physiology (I have a lot more at home). If you were to spend some time with these books you would discover rather quickly that, all in all, entomologists are boring writers. No zip, little spark. And that, in a nutshell, is why I like Jeff Hahn's new book Insects of the North Woods so much.

Photo and Cover: Insects of the North Woods, by Jeffrey Hahn. © Kollath-Stensaas Publishing.

Just looking at the cover of Insects of the North Woods you might be convinced that this is just a typical insect field guide. It's got some pretty pictures and, on the back, the obligatory author photo. But when you open the pages of this book, you quickly discover that it is not only as informative as you would expect from a University of Minnesota Entomologist, it's also entertaining. This book literally drips with Hahn's personality and sense of humor. Between talking about receiving a gift of a dead insect being every woman's dream when referring to scorpion fly mating rituals, and the mini scuba tanks that predaceous diving beetles use, you soon come to realize that this isn't just an entomologist reciting dry facts. Instead, this is an author who loves his subjects and who wants the reader to love them too. Like most people, I don't read field guides cover to cover, but with this book I have often found myself going through the book page by page because I don't want to miss one of Hahn's insightful comments (or one of his amusing analogies).

Besides the writing, this field guide has everything else that you'd expect a field guide to have, including great pictures (mostly by the author), a nice index system for finding the insect you're looking for, and a good, but not overly-done introduction. Though this guide concentrates on insects of the North Woods and so is, at least in theory, intended for use in northern Wisconsin, Michigan, and Minnesota, it is also the best book available for identifying insects in forests around the Twin Cities area and is a great first field guide for any budding entomologist. If you enjoy insects, or if you're just interested in knowing what some of the insects that flit about your trees are, then you shouldn't miss this book.

Jeffrey Hahn, Asst. Extension Entomologist

Many people in Minnesota, including the Twin Cities, that spent time outdoors during mid-September encountered large numbers of small dark-colored 'gnats'.  Upon closer examination, these insects turn out to be winged aphids (examples include soybean aphids, basswood aphids,and oat bird cherry aphids).  This has been a favorable summer for aphids and large numbers were produced.

Photo (left): 'Winged and wingless soybean aphids on buckthorn in spring'.  Christina DiFonzo, Michigan State University, Bugwood.org.

While the relatively cool summer had only a minor impact on the development and reproduction of aphids, these conditions had a more significant effect on aphids' natural enemies, such as lady beetles.  The cooler weather slowed down their rate of reproduction which ultimately allowed aphid numbers to thrive.

Aphids have a very unusual and complicated life cycle.  Many typically live on two different host plants.  They spend the summer on their primary host (e.g. soybeans for soybean aphids) feeding on sap and producing many generations.  Aphids reproduce parthenogenetically, i.e.eggs are not fertilized and only females are produced.  Females give
birth to live young.  

The end of summer brings shorter day length.  When combined with a few days of below average temperatures, these events trigger the production of a generation of winged females aphids (winged males are produced about a week later).  This year, that cold weather occurred at the end of August.  These winged aphids take flight and look for their alternative host plant (e.g. buckthorn for soybean aphids).  It is this migration that people have been seeing recently.

Once aphids land on their second host, they produce several generations of wingless aphids.  When the males arrive, they mate and then the females lay fertilized eggs.  Most aphids overwinter in the egg stage.  When spring arrives, the eggs hatch into wingless females which produces two or three generations.  Eventually a winged generation is produced, and these aphids fly back to their original host plants to start the cycle all over.

A common question people have asked is whether these insects will bite. Even though they are gnat-like, the answer is no.  They are harmless to us and do not bite like a mosquito or black fly.  However, it is possible that they may taste test people by trying to insert their
mouthparts into us which can result in a mild prick.  Fortunately,aphids then realize that we are not food.  

People have also wondered whether using a mosquito repellent will help keep these aphids off of us.  Repellents are designed to hide our chemical scent from blood-feeding insects, especially mosquitoes.  Since aphids are not seeking us out to feed on us, but just encounter us randomly, repellents will have no effect against them.  However, they are attracted to the color yellow so one step you can take to reduce the aphids that land on you is to avoid wearing any clothes of yellow color.

There have been a few reports of people applying insecticides into the air to try to kill the aphids around their homes.  This, of course, is an entirely futile gesture and just puts the individual at more potential risk from an accident with pesticides.  People should not
attempt to spray the aphids in their homes.

Fortunately, this migration of aphids is a short-lived problem and goes away on its own.  The greatest numbers of aphids were out for about a week during mid-September and have noticeably declined since then.  By October, there should be very few still actively flying.

Emily Tepe, Research Fellow, Department of Horticultural Science

If you walk through the St. Paul campus Display and Trial Gardens these days you're bound to see a lot of activity. No, I'm not talking about bees on the flowers (although there were a lot of those with the unusual warm weather in September), I'm talking about students. With the start of the fall semester comes a plethora of courses on plant identification, propagation, diseases and insects. The Display and Trial gardens offer a convenient and valuable living laboratory for these courses. In fact, throughout the year (save for a couple of months in the depths of winter) these gardens offer education to many people in the University community and beyond.

Photo 1 (left): Edible landscape portion of the University of Minnesota Display and Trial gardens. Emily Tepe

An Inspiring Outdoor Classroom

The Display and Trial gardens are comprised of various areas between Alderman Hall (home of the Department of Horticultural Science) and the Plant Growth Facilities on Gortner Avenue. Trees, shrubs, and hardscaping create the foundation for the gardens, and break it up into beds, each with their own theme. These themes change from year to year as new varieties are introduced, student projects are realized, and interesting gardening styles bring an opportunity to explore and experiment. The 2009 season brought some inspiring plantings and great educational opportunities.

These educational opportunities often get started while there is still snow on the ground, as students propose projects for the garden and begin designing beds and planting seeds in the greenhouse. Classes ,such as Professor, Neil Anderson's Floriculture Crop Production, research and schedule their assigned crops, working backwards from the planned finish date (mid-May), to assure their annual flowers are at the perfect stage for judging before being planted out in the gardens. Many of the varieties they grow are trials for major seed companies.

When spring arrives, students who have proposed projects for the gardens, begin breaking ground, laying out beds, sowing seeds, and eventually setting out transplants. They are responsible for maintaining their plantings throughout the season, keeping the beds watered, weeded and looking good. It's a great experience for students to take what they've learned in the classroom and put it all into practice. These projects bring the fresh ideas of students to the forefront, allowing them to experiment with new concepts and interesting designs, and even showcase some of their research.

By the time the gardens are in full swing, the St. Paul campus is pretty quiet. Most of the student body is gone for the summer, and the gardens become an inspirational outdoor venue for summer camps, youth enrichment programs, Master Gardener events, and horticulture industry field days. 

Photo 2 (right): Master Gardeners tour the Edible Landscape at the University of Minnesota State Master Gardener Conference. Emily Tepe

On any given summer day you are bound to find a group of high school students cutting flowers for a design and marketing program, or a flurry of youth in matching t-shirts tending a plot of vegetables; kept on task by their nurturing and enthusiastic mentors. Members of the local community often visit the gardens to view the new varieties released by the University, the vast array of annual flowers, and the creative ideas such as this year's Edible Landscape.

A Living Laboratory

Once classes start in September, University students begin spending a lot of time in the gardens. Many of the students in the introductory horticulture courses have never seen some of these plants before, and the gardens offer a close-up look at the topics they're studying. Tom Michaels, professor in the Department of Horticultural Science (teaching Plant Propagation this semester) said of the Edible Landscape portion of the gardens, "Students pass right by those beds every time they come to lab. They can't help but see examples of the food they buy in the produce department actually growing in front of them. It gives me the opportunity to talk about those foods and encourage them to stop by the beds and find examples of how chard differs from lettuce or dinosaur kale, or similarities and differences between beans and peas". The gardens are indispensable for the plant identification courses as well. Students find examples of hundreds of species, and with hand lenses and forceps, can scrutinize tiny flower parts to determine the plant family to which they belong.

Photo 3 (above): Plant pathology students observing symptoms of apple scab in the Display and Trial garden. Emily Tepe.

Horticulture students aren't the only ones spending time in the gardens. The Display and Trial Gardens provide a wonderful laboratory for plant pathology and entomology students as well. Todd Burnes, scientist in the Department of Plant Pathology, said numerous courses spend time in the gardens identifying and studying various plant diseases. While in the home garden, powdery mildew, leaf spot and white mold would likely prompt immediate action, here we aren't so hasty. The opportunity for students to observe the symptoms of diseases, collect samples and study them in the lab is worth a few ugly plants here and there at the end of the season. Entomology students roam the gardens, sweeping their longs white nets along the edge of the prairie strip, or carefully trapping unsuspecting insects on the zucchini flowers. Once back in the lab, they'll identify and study their specimens.

Photo 4 (below and right) : Powdery mildew on zinnias in the Display and Trial Gardens. Emily Tepe.

It is truly amazing the wealth of education that can be found in a garden. Here on the St. Paul campus, the Display and Trial gardens offer many people a chance to get up close and personal with flowers, grasses, trees, fruits and vegetables. And whether in class or just wandering through, there are countless opportunities to discover. Every garden offers such opportunities for young and old alike.

Jeffrey Hahn, Asst. Extension Entomologist

There have been various reports lately of trees weeping or dripping some kind of sticky substance. There have been different speculations about what causes this problem. Is it some kind of disease? Is it just sap? The answer: insects.

Photo: Typical aphids.  Jeff Hahn.

Aphids and certain scale insects feed in the phloem layer of plants using their needle-like mouthparts. They are not able to digest all of the sugars in the sap, and consequently, excrete a sugary liquid called honeydew. Honeydew is clear (can appear white) and is sticky. This material is not harmful to the health of trees but can be annoying when it coats deck furniture, cars, or other objects that are below infested trees. If this is a problem, try to remove it as soon as possible as honeydew can be very challenging to remove the longer it stays on.

Many ant species enjoy sweets and are attracted to honeydew. Some ants actually tend aphids to maintain their supply. Yellowjackets change their dietary habits during late summer and fall and are quite interested in the sugary content of honeydew. There can be so many yellowjackets attracted to a tree infested with aphids or scales that people may think that there is a nest in the tree.

Predators, especially lady beetles,may also be indirectly attracted to the honeydew. Of course they are interested in the aphids or scales that are producing the sugary liquid. One resident wanted to have a lady beetle larva identified. They were concerned because their tree was 'weeping' and these larvae were present. The owner was convinced that the larvae was causing the weeping and as a consequence started spraying them with an insecticide. Of course the lady beetle larvae were there to eat the aphids which were producing the honeydew.

Another consequence of honeydew is that it supports a fungus called sooty mold. Like the name suggests, it is black and sooty in appearance and is found on branches and leaves where honeydew is found. Although it is unsightly, sooty mold does not harm plants and should be ignored.

If you have a situation where you would like to reduce aphids, whether from the nuisance of the honeydew or from the insects themselves, there are several environmentally friendly options you can take. First, you can take a hose and direct a hard spray of water at infested leaves and branches. This knocks them off, effectively killing them. You can also apply a low impact insecticide, especially insecticidal soap or horticultural oil. These kill aphids while preserving natural enemies like lady beetles, lacewings, and syrphid fly larvae. Or just ignore them. As we approach fall, their activity slows down and they eventually stop producing honeydew.

Jeffrey Hahn, Asst. Extension Entomologist

Bird mites, especially the northern fowl mite, Ornithonyssus sylviarum, have been a common problem this summer entering homes and biting people. Bird mites are a major pest of chickens but will also parasitize many wild birds, such as pigeons, sparrows, starlings, and robins and are associated with nests that are built on or in homes and other buildings. Bird mites normally remain on birds and in nests throughout their lives where populations can grow to the tens of thousands.

If the mite populations become too large, or if the birds abandon their nest or die, the mites will move off en masse and look for an alternate food source and commonly enter homes. Bird mites are flat and the size of a pin-head, about 1/32 inch long. Although, they are very small, people can just barely see these mites. It also helps to see them when there are a lot of them around and they are moving.

Jeffrey Hahn, Asst. Extension Entomologist

Several people reported recently finding a small, ½ inch long, insect that resembles a preying mantid and a paper wasp. This unusual looking insect is known as a mantidfly. It looks like a preying mantid because of its large, front legs which are modified for grabbing prey. Mantidflies are commonly reddish brown with yellow with wings that are half brown along the front margin half and clear. Although they may not be frequently seen, mantidflies are reasonably common in Minnesota.

Mantidflies commonly parasitize spiders while other species lay eggs in the soil where the larvae prey on scarab beetle grubs, noctuid moth larvae, or social wasps. Adults feed on small insects they capture. Mantidflies are common on foliage in wooded areas during summer. People have generally found these insects outdoors but in at least one case a mantidfly was found that had accidently entered a house. Fortunately, these insects are harmless to people. If you should find one in your home, just release it outdoors.

Jeffrey Hahn, Asst. Extension Entomologist

 

The European elm flea weevil (EEFW), Orchestes alni and it's damage, was found on the University of Minnesota St. Paul campus during July.  It was found by Dr. Curtis Young, an extension entomologist at Ohio State University.  This invasive insect, common throughout Europe, was first found in the U.S. in 1982.  It wasn't found in the Midwest until 2003. It was first found in Minnesota in 2007 when an adult was collected on the St. Paul campus.

 

The adult EEFW is small, 1/10 - 1/8 inch long.  It is reddish brown with black spots or dark brown to black, with a long, conspicuous snout and large back legs which allows it to jump.  This weevil feeds on Siberian elm, Chinese elm, and hybrids with Asian parentage.  It rarely feeds on American elm.

 

EEFW overwinters as an adult and becomes active in the spring.  It moves to elm and feeds on the underside, windowpaning small areas, i.e. feeding on the lower surface of leaves but not chewing through.  A thin, opaque layer of leaf tissue remains.  Eventually, this chewed area dries up and fall out.  Don't confuse this injury with elm leaf beetle feeding which chews small oval holes in the leaves with the edge of the holes remaining green.

Jeffrey Hahn, Asst. Extension Entomologist

All species of willow, most poplar (but rarely quaking aspen), and occasionally birch and alder are susceptible to attack by the poplar and willow borer, Cryptorhynchus lapathi.  This insect, a type of weevil, is 5/16 - 3/8 inch long with a slender snout as long as its head.  It has a roughly textured black body with mottled cream to tan colored patches on its body and its legs, including the back 1/4 of its wing covers.

Jeffrey Hahn, Asst. Extension Entomologist

A spinach leafminer, Pegomya hyoscyami, is a small anthomyiid fly whose larvae attack the leaves of spinach, beets, chard, lambsquarter, and other plants.  This fly overwinters as pupae and the adults emerge the following April and May.  The adult is hairy, about 1/4 inch long, and grayish or brownish.  It lays eggs on the underside of older leaves.  A spinach leafminer larva hatches into a carrot-shaped, whitish maggot that lacks legs or an obvious head. 

The larvae tunnel into leaves, between the two leaf surfaces.  The mines are long and narrow at first, but eventually become an irregularly shaped blotch area.  These mines are opaque initially and then later turn brown.  The larvae are active for about two to three weeks before dropping to the ground and pupating.  Several generations can occur during one year.  This activity has little impact on plant growth but can be quite destructive to vegetables grown for edible greens. 

Jeffrey Hahn, Asst. Extension Entomologist

With the discovery of emerald ash borer (EAB) in St. Paul in May, many people have been asking for information on how to protect their ash with insecticides.  While there are several options available to home residents within 15 miles of the infestation, the question people should be asking now is when should I treat my ash.  In general insecticide applications should be made from early May until early to mid-June.  With that in mind, it is really getting late to be treating your ash any longer this summer.

Photo 1: EAB galleries in infested tree in St. Paul. Jeff Hahn

It is possible that Tree-age (emamectin benzoate), which is a professional use only product, can be applied into July because its mode of action targets the larvae and not the adults.  However imidacloprid relies on being taken up by the tree into the canopy and killing adults that feed on leaves.  Because it takes three to four weeks for imidacloprid to be translocated in trees, any applications that take place now, will have little impact in protecting ash.  This is particularly true for products available to the general public.  If you are thinking of treating your ash yourself now, don’t do it.  You will be just wasting insecticides.  The next window of opportunity for insecticide applications will be this fall or next spring.

There are many factors to consider if you are thinking about treating your ash for EAB.  For more information on insecticide options for protecting ash from emerald ash borers, please see the EAB Insecticide Fact Sheet (pdf).

Jeff Hahn, Asst. Extension Entomologist

There are several caterpillars that have been detected feeding on the leaves of blueberries recently. One species is the copper underwing, Amphipyra pyramidoides. This insect, also known as the pyramidal fruitworm, is bluish green with a thin yellow stripe running the length of its body along its sides and small whitish patches. It also possesses a conspicuous hump on the end of the abdomen and grows to about 1 ½ inches when fully grown. This caterpillar feeds on a wide variety of plants in addition to blueberry, such as trees (e.g. apple, basswood, maple, oak), shrubs (e.g. lilac, viburnum, and rose), and fruit including grape, raspberry, and currant.

You can also find forest tent caterpillars, Malacosoma disstria, in your blueberries. Also referred to as armyworms, these caterpillars are easily identified by their blue and black bodies, the distinctive white footprint shaped spots on their back as well as hairs that stick out along the sides of their body. These caterpillars are about two inches long when fully grown. Despite their name, they do not make conspicuous webs in trees. They commonly feed on many deciduous trees, including aspen, birch, maple, crab apple, apple, ash, oak, and elm.