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Extension > Yard and Garden News

Holiday cacti.jpgMany of us receive plants over the holidays as gifts or buy them to bring a little green into our homes during winter. Usually these plants are in full bloom and look terrific for some time. After the flowers dry up and drop off, indoor gardeners are sometimes left wondering how to care for these plants and more importantly - how to make them bloom again! Our Extension publication Cacti and Succulents has a very helpful section on "Holiday Cacti" that explains the affects of temperature and light on Christmas cactus (Schlumbergera bridgesii), Thanksgiving cactus (Schlumbergera truncata), and  - yes - Easter cactus (Rhipsalidopsis gaertneri). All three of these plants require short days and cool night temperatures to induce budding. Read more

January 9, 2015
After a mild December (11th warmest since 1895 on a statewide basis), the other shoe dropped over the first full week of January, with temperatures averaging from 7 to 10 degrees F colder than average through the first seven days of the month, somewhat analogous to the start of January last year. Brimson (St Louis County) reported the coldest temperature in the nation on January 4th with -28F and on January 5th Togo (Itasca County) reported the coldest in the nation at -29F. In fact over the first week of the month a few records were set:
New low temperature records included: -28F at Thief River Falls on January 4th; and -28F at Grand Portage on January 5th
New cold maximum temperature records include: -7F at both Grand Marais and Grand Portage on January 5th; and -8F at Wright (Carlton County) also on January 5th
In addition a new daily precipitation record was set for January 3rd at International Falls with 0.58 inches (associated with 7.8" of snow)
Read on ....

EAB is confirmed in Dakota County


Jeffrey Hahn, Extension Entomologist

(The following information is taken from a December 23, 2014 newsletter from the Minnesota Department of Agriculture)

Jeff Hahn, Univ. of MN Extension

Photo 1: Ash trees marked for removal due to EAB.

The Minnesota Department of Agriculture (MDA) confirmed an emerald ash borer (EAB) infestation in Dakota County. EAB was found in an ash tree in Lebanon Hills Regional Park in the city of Eagan, just north of the border with Apple Valley. The infested tree was detected through a routine visual survey of ash trees currently being conducted by the MDA. This survey is designed to find EAB in counties bordering the Ramsey and Hennepin County quarantine area.

Dakota County becomes the sixth county in Minnesota to confirm EAB. Additionally, EAB has also been found in Hennepin, Ramsey, Houston, Winona, and Olmsted (which was just confirmed this August) counties. These counties all have a state and federal quarantine established. The quarantine is in place to help prevent EAB from spreading outside a known infested area. It is designed to limit the movement of any items that may be infested with EAB, including ash trees and ash tree limbs, as well as all hardwood firewood.

This is especially important for Minnesota as there are approximately one billion ash trees present in this state. And all are susceptible to this invasive beetle. It is critical that people be aware of and follow the quarantine to minimize the spread of EAB. The biggest risk of spreading EAB comes from people unknowingly moving firewood or other ash products harboring larvae.

Every Minnesotan can help prevent EAB from spreading by taking the following steps:

• Don't transport firewood. Buy firewood locally from approved vendors, and burn it where you buy it;

• Be aware of the quarantine restrictions. If you live in a quarantined county, be aware of the restrictions on movement of products such as ash trees, wood chips, and firewood. Details can be found online at http://www.mda.state.mn.us/en/plants/pestmanagement/eab/regulatoryinfo.aspx; and,

• If you think you have seen an infested ash tree, go to www.mda.state.mn.us and use the "Do I Have Emerald Ash Borer?" checklist or contact MDA's Arrest the Pest Hotline by calling 888-545-6684 or emailing Arrest.The.Pest@state.mn.us to report your concerns.

For more information about EAB, see the University of Minnesota Extension publication, Emerald ash borer in Minnesota.

The original MDA news release can be found here.   



Spotted lanternfly is now in U.S.

Jeffrey Hahn, Extension Entomologist

A new invasive insect species from Asia, the spotted lanternfly, Lycorma delicatula, was discovered last month in Pennsylvania. Despite its name, this insect is not a true fly but is actually a type of planthopper which is related to aphids, leafhoppers, cicadas and similar insects.

Lawrence Barringer, Pennsylvania Dept of Agriculture

Photo 1: Spotted Lanternfly. Note spots on most of the wing and the lacey pattern on the wing tips.

A spotted lanternfly is a large insect, measuring about one and a half inches long. It is very distinctly colored and patterned. About 2/3 of the forewing is a light gray with small oval, black spots. The wing tips have a series of tiny rectangular black spots that give it a lacey appearance. The hind wings, when exposed, are brightly colored orange-red, black and white.

There are some native insects that could be confused with a spotted lanternfly, especially tiger moths and underwing moths which also can have red hind wings. However, moths are much better fliers compared to a spotted lanternfly. Moths also do not jump while a spotted lanternfly (and other planthoppers) are good jumpers.

The spotted lanternfly is known to attack about 65 different plant hosts in Korea, especially tree of heaven and grapes. It is also known to attack plants in the same genera as apple, willow, oak, lilac, rose, maple, poplar, and pine. Spotted lanternflies (like other planthoppers) damages plants by using its needle-like mouthparts to feed on plant sap.

It is unclear what the potential for damage would be if this insect becomes established in Minnesota. While there are many plants on which they are known to feed that are present in this state, a key to their ability to infest an area seems to hinge on the presence of tree of heaven which is not a native to Minnesota. In fact only one specimen is presently known to occur in the state. The question then is whether this insect could thrive on other plants. Time will tell.

If you find an insect that you believe is a spotted lanternfly, report it to the Minnesota Department of Agriculture on their Arrest the Pest line by calling 1-888-545-6684 (voicemail) or e-mailing them at Arrest.the.Pest@state.mn.us.

Click here for more information on spotted lanternflies.

Mode of action of Neonicotinoids

Karl Foord, Extension Educator - Horticulture




science.education .nih.gov


Photo 1: Paired nerves





www.animalhealth .bayer.com


Photo 2: Neural synapse


Insecticides

Insecticides can be characterized by the way in which they disrupt important biochemical functions. Many insecticides target the nervous system of insects by imparing the control of neural transmission. This can be done by disabling the system, and shutting it down. However, the majority of neural insecticides put the system in a continual state of ON giving the organism no opportunity to stop neural transmission. This results in uncontrolled and uninterrupted nerve firing. The insect that is exposed to such chemicals exhibits tremors, hyperactivity and convulsions. Sublethal doses of these chemicals can impair proper functioning behaviors such as flight orientation, and feeding while greater doses lead to a quicker death.

Normal neural transmission

A normal neural transmission proceeds down the nerve axon which splits into branches and eventually into smaller branches called dendrites. The dendrites of one nerve cell pair with the dendrites of other cells. The space between these two dendrites is call a synapse (Exhibit 1).

The electrical signal of the nerve is translated into a chemical message made up of so called neurotransmitter molecules. These molecules diffuse across the synapse and attach to receptor molecules on the dentrites of the paired nerve (Exhibit 2). The chemical message is translated back into an electrical message that then travels down this nerve cell's axon, and the neurotransmitter molecules are disassociated from the receptor molecules by an enzyme.

Neonicotinoid disruption of neural impulse

Neonicotinoid molecules enter the neural synapse and irreversibly attach to the receptors on the receiving neuron (Exhibit 2). The neurotransmitter enzyme cannot remove the imidacloprid molecule and the receptor is thus continuously active. The organism has lost control of neural transmission and either loses function or dies.

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