The gypsy moth is one of the most important forest pests in the Northeast. The caterpillar feeds on leaves of forest, shade, ornamental and fruit trees and shrubs. A single defoliation can kill some evergreens, but usually two or more defoliations are needed to kill hardwoods. Besides causing destruction or decline of the trees, loss of aesthetic, recreational and watershed values of ornamental trees, parks and forests occurs.
Caterpillars cause a public nuisance.
Small larvae chew pin holes in the leaves whereas larger larvae either partially or completely consume the leaf from the outer margin inward. They are often found on trunks of trees or underside of larger branches. Small larvae are dark brown to black and very hairy. Pupae are brown and teardrop shaped. A few threads of brown silk hold the pupae in place on the tree trunk.