The loopers feed on leaves for two to four weeks before spinning cocoons and pupating. Ten days to two weeks later a new generation of moths emerges. In North Carolina, there are five to six generations per year, mostly on crucifers. There is apparently a high degree of natural control of the cabbage looper by predators and parasites. Also a polyhedral virus disease seems to be a key factor in population changes of the cabbage looper.
Insecticides are available to control the cabbage looper when it becomes abundant.
Treatment is advised when 10 percent of the plants are affected. For specific chemical recommendations, consult the current North Carolina Agricultural Chemicals Manual.