University of Illinois Extension

Main Navigation

Bugs - Bug Review - University of Illinois Extension

Eastern Tent Caterpillar

These caterpillars are hairy and black with a white stripe down their back and a series of blue spots between longitudinal yellow lines. In spring their nests can be found at branch crotches of shade and fruit trees. Their favorite hosts include wild cherry, crabapple and apple.

cabbageworm

Eastern Tent Caterpillar Larva

cabbageworm

Eastern Tent Caterpillar Eggs

Habit

This insect overwinters in an egg mass attached to pencil-sized twigs. As new leaves emerge in spring, the eggs hatch and larvae build nests at branch crotches. During bright days larvae leave the nest to feed on foliage and return to the nest in the evening. Generally, during rainy weather or on very dark cloudy days, larva remain in the nest . In late spring, when caterpillars are fully grown (2 inches), they migrate to fences or other protected places and spin a cocoon. Adult moths emerge in late June/ early July, mate, and lay eggs. There is one generation per year.

Damage

Larva feed on foliage in the spring. If populations are high, they may defoliate a tree. Defoliated trees can become stressed allowing secondary problems to occur. Newly planted trees can be stressed easily.

Control

Non chemical: Remove webs by pruning out on a cloudy day or when darkness falls. And dispose of nest. Inspect trees for egg masses and remove before spring. Naturally occurring parasites help reduce populations of Eastern Tent Caterpillar.

Chemical: Contact your county Extension office for current pesticide controls.