Any of more than 3,500 species (family Arctiidae) of moths, many with furry or hairy larvae called woolly bears. Most adults have a thick body and white, orange, or green wings. At rest, the wings are folded rooflike over the body. The fall webworm (Hyphantria cunea) is a serious pest. The caterpillars construct webs over leaves, sometimes covering large areas with silken sheets. They pupate aboveground in a cocoon made of larval hairs and silk. The Isabella tiger moth (Isia isabella) attains a wingspan of 1.5–2 in. (37–50 mm). Black spots mark its abdomen and yellow wings.