Wingspan of 29-32 mm and a body length of 14-18 mm. Forewings are dark brown with distinctive grey-black markings. An inner spot is elongated and pale and the reniform spot is visible and kidney or arrow shaped. Hindwings are white with dark veins.
Two forms exist: a gregarious form and a solitary form. The gregarious form is velvety black above and green or yellow below. Pale lateral lines are also present. Three parallel lines are visible on the prothoracic plate and the head is shiny black. Solitary forms are cryptic, with a body colour of green-brown or pink.
Conical, ca. 0.5 mm in diameter. Initially pale yellowish in colour, darkening with age. Laid in batches covered with scale hairs on leaves.
Southern Asia, Oceania, Africa and the USA.
A range of agricultural crops including rice, millet, sugarcane, maize and cabbage.
Larval feed in full sunshine, on foliage, growing points and young stems. Large populations can entirely defoliate plants.