Wingspan of 12-15 mm and body length of ca. 9 mm. In males the upper two thirds of forewings are pale fuscous, sometimes tinged with ochre and flecked with white and black specks. The lower third of forewing is ochreous-white with white on upper edge margined with black-brown. In females the upper two thirds of forewing is pale-ochreous or pale grey-ochreous and bottom third like males. When wings are folded 3-4 diamond shaped areas are visible.
Fully grown larvae reach 11.2 mm in length. Body is green sometimes tinged with pale yellow. Five pairs of prolegs are
present and head capsule is pale green to pale brown mottled with brownish to black-brown spots.
Yellow to pale green in colour, oval and flattened, ca. 0.44 x 0.26 mm in size. Laid singly or in small batches on leaf surfaces.
Brassicas including cabbage, broccoli and cauliflower.
Larvae feed externally on leaves leaving a papery epidermis intact as translucent windows in leaves. Later instars feed more voraciously leaving just the leaf veins behind. Larvae also feed on stems and pods giving the crop a white appearance
Up to 20 in warm climates but more typically 4. 6 in temperate climates