The fall and spring cankerworms defoliate a variety of hardwood species in the spring. Hosts include the red and white oak groups, maples, elms, hickories, ash, and cherry. Heavy defoliation usually occurs in May and June, and can cause growth loss, mast reduction, and, if coupled with other stresses, may result in mortality. Their greatest impact is often felt in high public use areas where defoliation reduces the aesthetic value, and larvae and their droppings create a nuisance. Identifying the Insect.
Females are wingless.
The head is light and mottled with a yellow stripe along each side of the body. Coloring of both loopers varies with population density. Female moth laying eggs. Photo by John H. Ghent Spring cankerworm trap stick band. Photo by Bill Carothers Fall cankerworm larva.