Written By: Todd Lanigan, DNR Forest Health Specialist, Eau Claire, Todd.Lanigan@wisconsin.gov or 715-210-0150
As we head into September, fall webworm is starting to make its presence known. This native insect feeds on deciduous trees and shrubs and appears every year in yards and forests. Fall webworm forms loose webbing over branch tips and can completely cover a small tree with webbing. You will find both live and dead caterpillars, partially eaten leaves and frass (caterpillar poop) inside the webbing.

Fall webworm larvae inside webbing. Photo Credit: Wisconsin DNR