Yellownecked caterpillar

They feed in groups on leaves of cherry, crabapple, elm, maple, peaches, oak and walnut. Young larvae feed on soft tissue, leaving skeletonized leaves. Older larvae feed on the entire leaf. The last few stages do the most damage. They can rapidly defoliate ornamental and orchard trees if not controlled. Because they feed in groups damage may be localized to single branches. Single trees are more subject to attack than forest or orchard trees. Yellownecked caterpillars pose a serious, if occasional threat to pecan, hickory, walnut, oak, willow, honey locust and other trees and woody shrubs.