Jan Hamrsky / Diving beetle (Colymbetes fuscus) close up head portrait. Europe, June. Controlled conditions.

Will Watson / Diving Beetle (Colymbetes fuscus) resting on submerged log, captive, Herefordshire, England.

Jan Hamrsky / Diving beetle (Colymbetes fuscus), Europe, June. Controlled conditions.

Will Watson / Diving beetle (Colymbetes fuscus) on Hornwort (Ceratophyllum demersum), captive, England.

Kim Taylor / Larva of Water beetle {Colymbetes fuscus} Europe

Chris Shields / Illustration of Water beetle (Colymbetes fuscus),bottom left; Mayfly (Ephemeroptera sp.), centre; and Mosquito (Culicidae sp.) right; with larvae.

Jan Hamrsky / Diving beetle (Colymbetes fuscus), Europe, April, controlled conditions

Jan Hamrsky / Diving beetle (Colymbetes fuscus), Europe, April, controlled conditions