The tent is gradually enlarged as the caterpillars grow. The caterpillars become full grown in late spring. Most wander from the area of the tent and spin a white cocoon of silk, within which they pupate. The adult moths, which are light brown with faint light wavy bands on the wings emerge about two weeks later. The moths mate and the females then lay a single egg mass.
Tent caterpillars produce only one generation per year.
Forest tent caterpillar. Fall webworm adult moth. Tent produced by fall webworm. Although its life history is similar to other tent caterpillars, the forest tent caterpillar does not produce a permanent tent as do the other species. Instead, they make light mats of silk on trunks and branches that are used as temporary resting areas during the day.