Wingspan of 40-50 mm. Forewings dark brown with dark cross lines. A white or white bordered kidney shaped spot is present in the front half of the wing. The
sub-marginal line is yellow-white with 2 dents to form the letter M. Hindwings are grey, darker along the margins.
Final instars reach 35-40 mm in length. Body varies in colour from greyish-green to dark brown or black. A dorsal pattern of dark spots is present, shaped like a herring bone. Lateral sides of body with a yellowish stripe in addition paler stripes.
A wide range of crops but prefers members of the Brassicaceae, including cabbage, cauliflower, and brussels sprouts.
Young larvae feed on the underside of external leaves, leaving the veins. Older larvae bore into the heart of plants to feed depositing large amounts of frass. Larvae may also feed on inflorescences of broccoli and cauliflower.
