Whirligig beetles

Code QC109999

Specialised, gregarious, water-surface dwelling adephagan beetles with the general body shape of Dytiscidae but having the eyes divided into two parts, one above and one below the water surface. The forelegs are long and elbowed forward, the middle and hind legs short and paddle-like. These beetles thus are very distinctive and immediately recognisable to family level.

Gyrinids (suborder Adephaga) occur in both lentic and lotic habitats. Adults inhabit still or moving water where they swim in tight circles on the surface with the aid of surfactants secreted by the pygidial glands, predating mostly on terrestrial insects that fall on the surface film. Larvae crawl, fully submerged, , along the bottom (benthos). Four genera, comprising around 25 species, occur throughout Australia, with Macrogyrus being most abundant and diverse. No genus is endemic, but most species are.

Reference:

Lawrence, J.F. and Britton, E.B. (1991) Coleoptera. pp. 543-683. In: CSIRO, Insects of Australia. Volume 2. Melbourne University Press, Carlton, Victoria.