most species with distinctive broadly oval to spherical shape, strongly convex dorsally and flat ventrally. Tarsi appearing 3-3-3, but actually 4-4-4 with 3rd segment minute and some bilobed segments; short legs. Head often concealed by pronotum. Antennae short (8-11 segments) with a 3- to 6-segmented club. Many species are brigthly coloured, patterned with spots. some are shiny and smooth, others covered in short hairs. Larvae are elongate, soft-bodied, usually black with soft spines and long sickle-shaped mandibles.