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. Trees listed above are considered to be primary hosts of the fall webworm, i.e., trees where eggs are deposited and where larval development is usually completed. In several instances, however, larvae of the black race have been observed to feed and develop on foliage of other plants intermixed with primary hosts.
Adults emerge in spring with time of emergence varying by race.
Females lay their eggs in groups of 300 to over 1000 on foliage of host trees. Orange-race females may lay eggs in either single or double layers. Eggs usually hatch in 7 to 10 days. Larvae feed in colonies, and webbing of foliage begins with onset of feeding. Webs are enlarged to enclose additional leaves as webworms feed and grow.