The male is a small, brown, hairy moth with clear wings. Egg -The yellow egg is slightly oblong or spherical, about 0.8 mm by 1.0 mm. It is found in the mother's bag, usually in her pupal exuviae. The head and forward parts are dark and sclerotized the remainder is pale amber. Pupa -The pupa is dark brown.
Males are slender posteriorly, and females are cylindrical.
The pupal stage is spent inside the bag. Arborvitae is highly susceptible. Damage -A single bagworm does relatively little damage. Damage is most noticeable on ornamental plantings rather than in forests and woodlands. Populations vary, but occasionally bagworms become extremely abundant, alarming homeowners.