Unlike eastern tent caterpillars, the fall webworm feeds within its tent, which encloses foliage at the end of branches. Defoliation by fall webworm caterpillars does not usually cause damage to the tree, since they feed in late summer or fall, just before leaf drop. Control of fall webworm is usually for aesthetic benefit.
The hairy caterpillars vary in color and come in two forms: red-headed and black-headed. They tend to be pale yellow or green in color, though some may be darker. Each segment of the caterpillar’s body has a pair of spots on the back. At maturity, the larvae may reach one inch in length.
The adult fall webworm moth is bright white, with a hairy body. Like most moths, the fall webworm is nocturnal and attracted to light.