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. Eastern tent caterpillars prefer cherry, plum, peach, apple, hawthorn and related plants. If the food plant is defoliated they may move to less preferred hosts. Caterpillars leave their tents to feed on leaves and can quickly defoliate sections of a tree. Caterpillars may migrate and wander before they form a cocoon which may bring them into contact with homeowners.