Adult females commonly pupate and deposit egg masses on motor vehicles, especially trucks and recreational vehicles that are parked near or under trees. Females lay eggs on the trunks of trees, each egg mass including several hundred eggs. May. The young caterpillars are black and hairy, later becoming mottled gray with tufts of bristlelike hairs, and blue and red spots on the back. There is one generation per year. Gypsy Moths have preference for oaks, but they will attack the foliage of most trees and shrubs.
Adults differ in appearance, males being brown with a fine, darker brown pattern on the wings.
Females are nearly white, with a few dark markings on the wings. Females do not fly. Caterpillars climb trees and feed mostly at night. They are capable of denuding foliage from trees, and this activity will kill many trees if repeated over a few years. Trees also become weakened and more susceptible to diseases and wood boring insects.