Fall Webworm

Description:

This is the caterpillar of the Fall Webworm Moth. Larva: two distinct races - northern larvae have black head, yellowish or greenish body with dark dorsal stripe and long whitish hairs arising from black and orange tubercles located along sides (in each cluster of hairs, at least one hair is about twice as long as the others); southern larvae have orange or reddish head, yellowish-tan body with orange to reddish tubercles and brownish hair. Larva have extremely long hairs, greater in length than four or five body segments, which is an identifying characteristic. This one was photographed in Edgefield County, SC.

Habitat:

Range is all of United States and southern Canada plus northern Mexico accidentally introduced from North America to Yugoslavia in the 1940s, and has since spread throughout Europe; later introduced to northern China and North Korea. Found in weblike tents in branch tips where clusters of caterpillars strip foliage (by contrast, eastern tent caterpillar nests are built in tree crotches).

Notes:

Caterpillars are found June to September or October in the north; May to October in the south. Larva are most often noticed when they reach final instar and wander out of their home trees to find a place to pupate. About 120 species of hardwood trees have been recorded as larval hosts in the north including alder, apple, ash, birch, Box-Elder (Acer negundo), cherry, elm, mulberry, poplar, willow. In the south, common hosts include ash, hickory, maple, mulberry, oak, pecan, poplar, redbud, sweetgum, walnut, willow; preferences for different host plant species appear to be regional and seasonal.