During the fall, larvae of fall webworms first spin webs around them on small branches of trees. Then inside the net these larvae feed voraciously on the leaves and skeletonize them. In case of severe cases, they can defoliate some branches of a tree. While feeding on the leaves, these develop into mature larvae.
Fall webworms overwinter as pupae in the soil, under the leaf litter or in the cracks. Adults of fall webworm generally emerge from pupae in June and their females lay eggs on the lower surface of leaves. These eggs hatch within a week into small larvae that start spinning a silken web around leaves on which they start feeding. These larvae remain inside the web until they mature. After maturity, larvae fall of the tree on the ground for pupation. Under favourable conditions, fall webworms can complete two generations within a year.