If you’ve been out walking around Devil’s Lake State Park recently you may have seen those green flags stuck to the side of some of the trees. If you get up close, you’ll see lots of little caterpillars just above the flags. Those little wormy things are Gypsy Moth larva. I know, YUK!
Invasive European Gypsy Moths entered the US in 1869 in an attempt to breed a better silkworm and they soon escaped. The moths are a voracious leaf-eating insect that can feed on most types of trees and shrubs found in North America. If there are enough of them, Gypsy Moth caterpillars can strip an entire forest of leaves during May and June. Needless to say, trees need their leaves and soon become weak and die under the pressure of Gypsy Moths.
Here in Wisconsin, there is a program to eradicate Gypsy Moths which for the most part involves aerial spraying of Bacillus thuringiensis (Bt) and Foray or in areas with other moths and butterflies that are to be protected, Nucleopolyhedrosis Virus (NPV) and Gypchek is used. You can learn more about these chemicals here. Currently park staff is marking and monitoring the Gypsy Moth population in the park and the WDNR will decide when/if to spray.
How Do I Know When They Spray?
Aerial spray activity information is updated on the Wisconsin DNR’s toll-free gypsy moth information line: 1-800-642-6684. (Press 1 to listen to a recording about the latest update from both programs.) You can also sign up for email notifications here.
***Obligatory Disclaimer: This website is NOT associated with the Wisconsin Department of Natural Resources. The views expressed in this blog are mine and do not represent the views of the Wisconsin Department of Natural Resources.