The impact was less in moist years, but still substantial 1 . The adult is an oval green beetle, 6.0 to 7.5 mm long, with a hard covering on the head, thorax and abdomen that forms a carapace extending beyond the body like the shell of a tortoise. There is a brown spot at the center top of the wing covers and the underside is black.
Females are slightly larger than males.
The larva has prominent lateral spines and a forked tail spine on which it accumulates moult skins and excrement. This is held as a protective parasol over the insect's back, although some parasite species orient the parasol. The pupa is a flat brown oval with a margin of black ray-like spines. It is attached to a leaf or stem by its tail segments and if disturbed it flaps like a hinge. The eggs are laid in cycles of approximately 6 weeks with 7 week rests.