Caterpillars are grayish with five pairs of blue spots and six pairs of red spots along their back. There are yellow markings on the head. Pupae are reddish-brown. Male moths have a wingspread of 1 inches. They are light tan to dark brown and have blackish wavy bands across their forewings with arrowhead markings near the leading edge.
Female moths are nearly white with faint, dark wavy bands on the forewings.
They are much larger than the males, with a wingspread of up to 2 inches, but they do not fly. The antennae have a feathered appearance in the males but are long and thin in the females. The adult moths do not feed and live for only a few days. In its caterpillar stage, the gypsy moth can feed on more than 500 different species of trees and shrubs. Millions of acres of trees are defoliated every year.