|Fall Webworm (Hyphantria cunea)Nest. The Fall Webworm is a species of white moth that lays its eggs on the undersides of leaves in late summer and early fall. Caterpillars hatch a week later and are highly variable in coloration, ranging from pale yellow to dark gray. Caterpillars consume the leaves of the tree for four to six weeks before creating a cocoon in the leaf litter under the tree to overwinter. Most damage to the trees is cosmetic. These webs should not be confused with those of the Eastern Tent Caterpillar, which are visible in spring.