Pest description and damage These gregarious caterpillars spin web-like tents in branch tips of deciduous trees including apple, cherry, peach, pecan, English walnut, black walnut, ash, boxelder, birch, chokecherry, elm, hickory, linden, poplar, sycamore, white oak, willow, and sometimes roses and other shrubs. The caterpillars feed on enclosed leaves as the tent fills with dead leaves and frass. Young caterpillars are pale greenish or yellow with a dark stripe down the back and a yellow stripe along the sides. Long silky hairs arise from yellow and black tubercles. When mature, the caterpillars are covered with yellow or rusty- to black-colored silky hairs. Adults are bright white with orange and black markings on the underside of the abdomen. Whitish moth scales cover and protect masses of 200 to 500 greenish eggs. Larvae can defoliate young trees.
For biology, life history, monitoring, and management
Cottonwood (Populus)-Fall webworm
See Table 2 in: