Ash (Fraxinus)-Fall webworm

Hyphantria cunea

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 over 1.25 inch in length, covered with yellow to rusty- to black-colored silky hairs. Adults have a 1-inch wingspan and are bright white with orange and black markings on the underside of their abdomens. Whitish moth scales cover and protect masses of 200 to 500 greenish eggs.

For biology, life history, monitoring and management

See:

Cottonwood (Populus)-Fall webworm

See "Caterpillar" in:

Common Landscape Pests

Management-chemical control

See Table 2 in:

Chemical Control of Landscape Pests