These are grayish brown moths with small silvery white marking on the edge of the front pair of wings. They lay eggs singly on the underside of the leaves or sometimes in a small batch. They feed on leaves (leaving big holes on leaf surfaces), and continue feeding into the base of heads where they eventually reside. Pupa are found in loose white cocoons attached to the underside of the leaves. They do not overwinter in the Midwest so the adults migrate from southern states in spring. They also attack spinach, Swiss chard, and other brassica greens.

Diamondback moth – The adults are small, grayish-brown moths with three diamonds on their body, which are more distinct on males than females. They lay yellow eggs singly underside the leaves near veins. The larvae are green and feed under the leaf epidermis first and later on feed on the outer layer of the leaf. May overwinter as adult in protected areas but not very common in the Midwest where it moves in large numbers as adults from the southern states.

Control for cabbage looper and diamondback moth: Attacked by parasitic wasps, green varieties of cabbage are less attractive to the moth, row covers, destruction of crop residues after harvest, and Bt. Kurstaki or an insecticide recommended in your state.