The adult beetles measure about 8-9 mm in length, smaller individuals may occur when infestation levels are high (Mally 1924, Tooke 1955). They vary in colour from rust brown to a dark brown appearance. There is a black X mark over the elytra with a white stripe on the scutellum. These markings may vary considerably from being prominent to very feint.
The larvae are slug-like in appearance, green and covered in a sticky slime (Mally 1924, Tooke 1955). The fourth instar larvae measure 11 mm in length and 4 mm in width. The head is black and the body has a median dorsal line and a black lateral stripe. A black shield shaped dot is present on each segment of the larvae. The frass excrement of the larvae extends behind the body like a filament and often curls and sticks to the larvae.