Statewide Forest Health

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.

Stump treatment to prevent heterobasidion root disease (Annosum)

Posted on by colleenrobinson
Applying a preventative treatment to a fresh pine stump using a backpack sprayer.

Applying a preventative treatment to a fresh pine stump using a backpack sprayer. Photo by: Linda Williams, WI DNR.

There are currently two products available to treat fresh pine stumps to prevent new infections of heterobasidion root disease (HRD), which was previously called annosum. The products are Cellu-Treat and Rotstop-C. Both are water soluble and can be sprayed on the stump. Sporax, a granular/powder product, was previously available but is no longer being manufactured. If you still have a supply of Sporax you can continue to use it. The one-page factsheet on HRD (Annosum) has been updated with information on where to purchase the available products.

For more information on Cellu-Treat and Rotstop-C please check out these websites:

Written by: Kyoko Scanlon, forest pathologist, Fitchburg (Kyoko.Scanlon@Wisconsin.gov), 608-275-3275.

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” →