NORTHWOODS - Around this time, people start noticing webbed nests on tree branches in their yards and woods. Fall webworm activity peaks in August. The insects are native to northern Wisconsin and live on hardwoods. Caterpillars form nests and feed on the leaves inside the nest.
"They do make a very messy web nest and people would be seeing that at this time of year," DNR forest health specialist Linda Williams. "The web nests that we see in trees in the fall will be out at the ends of branches."
Fall webworms are active every year, but come out in greater numbers during some years. Last year, the webworms were especially active.
"With these caterpillars coming along and eating the leaves off now, it's not a major health threat to the tree. The tree is already starting to think about shutting down for the winter," Williams said.
DNR forest health specialists also found oak wilt in a new place in the Northwoods. Oak trees in Conover have now been infected.
The DNR also reports northern Vilas County was hit hardest by defoliation from spruce budworm this year.