The eastern tent caterpillar is one of the earliest defoliators of ornamental trees; and although the feeding damage many not initially kill a tree or shrub, it may reduce the plants ability to produce food, thus increasing susceptibility to secondary pests such as wood-boring insects.
Eastern tent caterpillars host primarily on ornamental cherry, wild cherry, and apple, but also other shade, forest, and fruit trees. Spindle-shaped egg masses encircle twigs and can be seen from late summer until early spring. In spring, look for silken tents in crotches of trees. The caterpillars are furry and bluish with black heads and a white stripe down the back. Defoliation is usually complete by mid-May. When damage is severe, only larger veins and leaf petioles remain. The chunky, chocolate brown moths have narrow white bands on their wings and are attracted to light.
The winter is spent in masses of 100-300 eggs. Hatching occurs in early spring, and the newly emerged, gregarious larvae construct tents. They leave the nest on warm sunny days to feed on nearby foliage. When full grown, larvae wander in search of pupation sites. Pupation takes place in silken, yellow-dusted cocoons on trees and other vegetation and on fences, buildings, and other structures. Adults emerge in July. Reduced growth and branch damage may result from heavy or repeated defoliation.