Hosts include cabbage, turnip, beet, collard, cauliflower, kale, rutabaga, radish, kohlrabi, mustard, rape, horseradish, shepherdspurse, and purslane. North Carolina cabbage webworms do no damage to spring cole crops. In late summer or early fall, however, young plants of the fall crop are subject to attack. By boring into buds, stems, and stalks, webworms destroy or disfigure buds and sometimes kill entire plants. Plants with destroyed buds will produce secondary buds but these are not likely to mature into marketable heads by harvest.
Webworms feeding on the outer leaves of older plants are harmless.
Webworms are enclosed by protective silken webs, often hiding along leaf veins on the underside of leaves. They feed during the day, but are fairly inactive during cold weather. Cabbage webworm moths deposit approximately 300 to 350 eggs on host plant buds. About 3 days later, larvae emerge and feed in the buds, eventually moving to the outer leaves where they spin webs and continue to feed along large leaf veins. They pupate among shed leaves or other refuse on the ground.