The masses enclose the needles on which larvae feed. At first the webbed mass may e only one or two inches long but may later become quite large and contain several larvae. Seedlings up to two feet tall can be defoliated by the larvae of a single nest. Infestations on larger trees cause partial defoliation, loss of growth and poor tree appearance. Web Life History and Habits - Pine webworms overwinter as pupae in the soil.
Adults emerge in the spring, mate and lay eggs on the needles.
On hatching, young larvae mine the needles. Older larvae feed on needles and construct the web mass. Larvae continue to feed within the expanding web until mature, then drop to the ground and pupate in a cell in the soil. As with many moths, the speed of development depends on temperature. There are probably two generations per year in south Georgia.