In Alabama and much of the southern region, both races occur and both solid white and spotted adults are found. Moths pictured in Photo 3 are representative of the majority of fall webworm adults usually encountered in our area. Bodies are tan throughout most of the developmental period but become darker in the last stage. Caterpillars of both races are densely clothed with hairs that arise in clumps from tubercles. Full-grown webworm larvae are 1 to 1 inches long.
Hosts are almost wholly hardwoods but at least one conifer, baldcypress, is included.
Food trees preferred by the webworm vary by region and, in the southern region where both races occur, also by race. Webs on pecan, persimmon, the cherries, and sourwood are predominantly, or wholly, orange race, and those on sweetgum, willow, and mulberry are black race. The black race also infests pecan and persimmon but to a lesser extent than the orange race. Several other species of trees serve as hosts for the webworm in Alabama but are infested somewhat less frequently. Colonies of both races have been found feeding on elderberry, hickories, and sycamore, and black-race colonies have been recorded on ash, blackgum, elm, redbud, and baldcypress.