The now mature larvae attach their bags to branches or other objects and change into adults. The adult male is a small, gray, clear-winged moth that resembles a wasp. The female is wingless and legless and never leaves the bag. Males emerge in September and mate with the female through the bag entrance. The female then produces her eggs and dies.
Eggs mature over winter inside the bag, and the cycle repeats the following year.
Small infestations can be picked off by hand once the larvae are large enough to see easily. However, any insecticide spray will be more effective if used on young larvae that are actively feeding. In Kansas, start looking for the new hatch about the middle of May. Wait a week after seeing the first larvae emerge to allow those still in the bag to make their appearance. Insecticides commonly used for controlling bagworms include Orthene, Dursban, Malathion Sevin and Diazinon.