Larvae form a dense silken web usually in the crotch of small limbs which is used as a refuge at night and during rainy spells. The tent is expanded as the caterpillars grow. The forest tent caterpillar , M. disstria H bner , has a series of keyhole shaped white marks on the back. It does not form a tent and is found on a variety of hosts but prefers oaks in Texas. Caterpillars have a series of white dashes on the back.
Caterpillars have one black segment but lack white markings on the back.
Fall webworms form loose silken webs around foliage upon which they are feeding rather than dense webs in crotches of branches which they leave to feed. The winter is spent as a hard mass of eggs that encircle a twig. There is only one generation per year of tent caterpillars so all activity is usually over by May or June. Caterpillars have chewing mouthparts. Adults have siphoning mouths.