Insect

Treat your ornamental ash trees for emerald ash borer this spring

Posted on by colleenrobinson
A yellow ornamental ash tree at peak fall color. This tree is worth treating to protect it from being killed by emerald ash borer.

High-value ash tree at peak fall color.

March is a good month to consider insecticide treatments for high-value ornamental ash trees this spring. Emerald ash borer (EAB) has been found in 42 Wisconsin counties and is expected to be more than 99% fatal to ash trees that are not protected with insecticide every 1-2 years. Many insecticides used in EAB treatments are applied between mid-April and mid-May, and now is a good time to contact a tree service or other pesticide application business if arranging for professional insecticide treatments.

Property owners with susceptible ash trees should consider a number of factors when deciding to treat their ash trees, including financial cost, tree condition and location, the shade a tree provides, its contribution to property values, and aesthetic view. Homeowners should also consider the financial cost of removing a tree that is killed by EAB, and the benefits that a dead tree no longer provides.

Continue reading “Treat your ornamental ash trees for emerald ash borer this spring” →

Emerald ash borer new locations in Wisconsin

Posted on by colleenrobinson

Emerald ash borer (Agrilus planipennis) continues to be found in new areas. Regional Forest Health Updates were not sent during the 2016/2017 winter, so the list below includes new EAB finds from the last few months. Wisconsin continues to track EAB at the municipality or township level; infested areas are shown in green on the map below. If you know you have EAB please contact us with that information so we can verify the infestation and update the maps. If your area:

  • is not shaded in green on the map please contact DNR or
  • is not shaded at all on the map please contact DATCP.

You can reach both agencies from the menu options when you call 1-800-462-2803. Continue reading “Emerald ash borer new locations in Wisconsin” →

EAB parasitoid releases continue in Wisconsin

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EAB parasitoid adults arrive in cups for release in EAB infested areas.

Releasing adult Spathius galinae for EAB biocontrol.

EAB biocontrol releases in Wisconsin will continue in 2017. Wisconsin first released parasitoids to help control emerald ash borer (Agrilus planipennis) in 2011. Our first releases in northeastern Wisconsin occurred in 2016 when we released the two larval parasitoids Tetrastichus planipennisi and Spathius galinae, as well as the egg parasitoid Oobius agrili. These parasitoids are incredibly small, but they find EAB larvae and eggs just fine, helping to reduce the population of EAB. These parasitoids will not stop EAB, but they are an additional tool we can use to slow the population growth.

Locations in Wisconsin where EAB parasitoids have been released 2011-2016. Map created by Bill McNee.

Locations in Wisconsin where EAB parasitoids have been released 2011-2016. Map created by Bill McNee.

Written by: Linda Williams, forest health specialist, Green Bay (Linda.Williams@Wisconsin.gov), 920-662-5172.

Financial assistance is available for controlling invasive species.

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Looking for a financial assist in your efforts to control invasive species?

The Wisconsin Invasive Species Council website lists 61 different grant opportunities that are available from Federal and State agencies as well as private foundations. The list is searchable by applicant (tribe, government agency, company, non-profit, individual) and type of invasive organism (plant, animal, aquatic, invertebrate, disease). All but one has a link that takes you to more information or a contact person.

Why not take a few moments to explore these opportunities?

Written by: Michael Putnam, invasive plants program specialist, Madison (Michael.Putnam@wisconsin.gov), 608-266-7596.

Eastern tent caterpillars and forest tent caterpillars emerging soon

Posted on by colleenrobinson

If the weather warms up a bit, we could see eastern tent caterpillars (Malacosoma americanum) and forest tent caterpillars (Malacosoma disstria) hatching before the next forest health newsletter. These are both early spring caterpillars and hatch very soon after bud break.

Web nests and caterpillars will be small at first. Eastern tent caterpillars with pen.

Eastern tent caterpillars with pen. Web nests and caterpillars will be small at first.

Eastern tent caterpillar will make a web nest that can often be seen on wild black cherry along roadsides, although they also like to feed on crabapple, apple, and a few other species. Forest tent caterpillar does not make a web nest and prefers to feed on aspen and oak.

Continue reading “Eastern tent caterpillars and forest tent caterpillars emerging soon” →

Box elder bugs and lady beetles become active as weather warms.

Posted on by colleenrobinson
Multicolored Asian ladybeetles have a range of colors and spot numbers.

Multicolored Asian ladybeetles

If you had box elder bugs or multi-colored Asian lady beetles congregating on your house last fall, you’re probably starting to notice them appearing in your house again as the weather warms this spring. Last fall they were able to find a place on/in your house to overwinter and now they are attempting to leave your house to head back into the fields where the beetles, like all ladybugs, will feed on aphids and the box elder bugs will feed on the sap of certain trees.

Continue reading “Box elder bugs and lady beetles become active as weather warms.” →

New invasive insect: brown marmorated stink bug

Posted on by colleenrobinson

The invasive brown marmorated stink bug (BMSB) is establishing in Wisconsin. BMSB is an agriculture, garden and home pest. Action to control populations may be needed in coming years.

An adult Brown Marmorated Stink Bug. Adults are ½ to 5/8 inch long, shield-shaped, mottled brown to gray with light and dark banding on the antennae and alternating light and dark spots on the end of the abdomen.

An adult brown marmorated stink bug. Photo by P.J. Liesch, University of Wisconsin-Madison Insect Diagnostic Lab.

BMSB is native to eastern Asia and was first officially found in the U.S. in 2001. The discovery of BMSB juveniles and the first noted pairs of mating adults in 2016 are continued signs that this invasive pest is establishing and reproducing in Wisconsin. We also had the first reports of BMSB feeding on plants, not just overwintering in structures. We expect populations will continue to increase in coming years.

 

A map of counties where BMSB has been confirmed or is suspected as of October 2016 was created by P.J. Liesch, University of Wisconsin-Madison Insect Diagnostic Lab and Bill McNee, Wisconsin DNR.

For information about how to identify BMSB and how to manage nuisance populations check out these publications.

Written by: Mike Hillstrom, forest health specialist, Wisconsin Dells (Michael.Hillstrom@Wisconsin.gov), 715-459-1371.

Unwanted in Wisconsin: hemlock woolly adelgid

Posted on by colleenrobinson
Hemlock woolly adelgid is an exotic aphid-like insect that produces distinctive small balls of white wool at the base of hemlock needles.

White balls of hemlock woolly adelgid ‘wool’ on a hemlock twig in Maryland.

If you work around hemlock trees, keep an eye out for signs of hemlock woolly adelgid (HWA), an aphid-like insect that was introduced to eastern North America and is fatal to most hemlock trees.

HWA produces distinctive, small balls of white wool at the base of hemlock needles. Recently, a number of infestations have been found in western Michigan and there is a risk that the pest could spread across Lake Michigan into Wisconsin. Hemlock woolly adelgid has not been found in Wisconsin.  Continue reading “Unwanted in Wisconsin: hemlock woolly adelgid” →