Grayish, with five pairs of blue spots and six pairs of red spots along their back, the caterpillars have yellow markings on their head. From June to August, larvae enter the pupal, or resting, stage. Pupae are reddish-brown. Male moths have a wingspread of about 1 inch. 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.
With a wingspread of up to 2 inches, female moths are much larger than males, but they do not fly. The antennae have a feathered appearance in the males but are long and thin in the females. 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. The pests can defoliate millions of acres in a season.