Fall Webworm

Fall Webworm (hyphantria cunea) The adult moth has a wing spread of 1-2 inches and is primarily white with black spots sometimes found on the wings. The legs and body occasionally have orange markings on them. The eggs are light green to yellow and laid in masses of several hundred. After about 10 days, the eggs hatch and the larvae feed gregariously. Mature larvae are about 1 inch long and a pale yellow-brown or gray. The body is covered with long, whitish hairs which protrude from black and orange tubercles.

The larvae feed until about mid-September and overwinter in the pupal stage. The pupae can be found in soil litter, tree trunks, or on buildings near infested areas.

Trees commonly attacked include more than 100 species of deciduous forest, shade and fruit trees, with preferences varying from region to region. Fall webworm occurs throughout the United States, southern Canada and parts of Mexico.

The caterpillars sometimes spin copious amounts of webbing to feed in. The webbing can sometimes extend until entire large branches of the tree are completely enclosed. Young larvae feed primarily on the upper and lower epidermis of leaves, giving the leaves a skeletonized appearance. Older larvae feed on the entire leaf and may completely consume it.

For control products and more information please see our Caterpillars and Moths Control page.