Larvae chew large holes in leaves of cabbage family plants and many other vegetable crops. May damage whole plants.
Moths emerge from overwintering pupae in mid-spring and lay eggs on leaves; larvae feed 2 to 4 weeks, then pupate 10 days in cocoons attached to stems or leaves. Three to four generations per year.
Scout for and destroy eggs on undersides of leaves. Handpick adults several times weekly; attract native parasitic wasps by planting pollen and nectar plants; till in crop residues before adults emerge in spring; spray larvae with BTK or garlic oil. As a last resort for severe infestations, spray with pyrethrin.
Keep Reading: Cabbbage Growing Guide
Larva photo: R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, Bugwood.org
Moth photo: Keith Naylor, Bugwood.org