Family: Dystiscidae, Predacious Diving Beetles view all from this family

Description 1-1 5/8" (25-40 mm). Oval. Dark brown or black with yellow along sides of prothorax and elytra, all often with greenish tinge. Female has 10 parallel grooves in each elytron. Legs are yellow or brownish.

Food Less vigorous aquatic animals, including small fishes, tadpoles, and insect larvae.

Life Cycle Eggs are thrust singly into underwater plant stems. Larvae hunt prey and, when fully grown, creep out of the water to pupate in moist earth. Adults overwinter and live 3 years or more. The larvae are voracious predators. The largest species are the Harris' Diving Beetle (D. harrisii) and the Pan-temperate Diving Beetle (D. marginalis), both 1 1/2-1 5/8" (38-40 mm), with yellow on the front and rear margins of the pronotum. They occur in the northern United States and Canada. The Western Diving Beetle (D. marginicollis), 1 1/8" (28 mm), has yellow only on the sides of its pronotum. The Understriped Diving Beetle (D. fasciventris), 1-1 1/8" (25-28 mm), has dark marks below its brownish-red abdomen. The Vertical Diving Beetle (D. verticalis), 1 1/4-1 3/8" (33-35 mm), has yellow stripes on its elytra and is black underneath. The Hybrid Diving Beetle (D. hybridus), 1-1 1/8" (25-28 mm), has yellow bars across the tips of its elytra and is black underneath.

Habitat Ponds, pools, streams, and rivers.

Range Throughout North America.