Carpenterworm (Prionoxystus robiniae) - The carpenterworm is widely distributed in the United States and southern Canada where it breeds in a variety of hardwoods. In Colorado, the insect is most common in shelterbelt settings in the eastern portion of the state. The adult is a large, stout-bodied moth with mottled forewings. The female is of lighter coloration than the male and has a wingspan of about 3 inches. Full-grown larvae are greenish white with a shiny, dark brown head, approximately 2-3 inches long, and they have very few, simple hairs on their surface.