Larvae feed within the web, eating th etender parts of leaves and leave the larger veins and midrib. There are two to four generations of fall webworms each year in Texas. The last generation of the year, which occurs in the fall, is usually the most damaging and gives the insect its name. Fall webworms overwinter as pupae on the ground or on rough tree bark. The moths emerge from silken cocoons in the spring to disperse and mate.
Female moths deposit hair-covered egg masses on the undersides of leaves of their food plants.
An egg mass may be deposited in either a single or double layer and can contain up to 600 eggs. Soon after webworm eggs hatch the larvae begin to build a silk web. As larvae consume leaves within the web, they expand the web to take in more foliage. The life cycle from egg to adult requires approximately 50 days. Control Fall webworms can often be controlled without insecticides by removing and destroying any leaves that contain egg masses.