The cabbage worm is light green, velvety and slugish. It can be 2.5 cm or longer and the legs on the last body segment extend backwards.
The adult imported cabbageworm is a white or whitish-yellow moth with black spots on its wings. New larvae are pale green in colour and can be found chewing on the underside of the host leaves. As they mature they chew through the leaves and leave a dark green fecal matter.
The imported cabbageworm larvae will damage the leaves of the plant which can reduce yield; however, once the crop has begun to head, the chewing and the fecal waste can contaminate and render the harvested crop unmarketable.