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Great Diving Beetle

Great Diving Beetle ©Jack Perks

Great diving beetle

The Great diving beetle is a large and voracious predator of ponds and slow-moving waterways. Blackish-green in colour, it can be spotted coming to the surface to replenish the air supply it stores beneath its wing cases.

Scientific name

Dytiscus marginalis

When to see

January to December

Species information

Statistics

Length: 3cm
Common.

About

The Great diving beetle is a very large diving beetle that can be found in ponds and slow-moving water. It is a voracious predator, hunting smaller invertebrates, tadpoles and even small fish. The larvae are large, fearsome-looking beasts, with big, biting jaws: they look a bit like pale brown, underwater Devil's Coach Horses. They use damp soil by the edge of the water to pupate in. Adults can be spotted poking the tips of their abdomens out of the surface of the water in order to replenish the air supply stored beneath their wing cases.

How to identify

The Great diving beetle is blackish-green in colour, with a yellow border to the thorax and around the wing cases. It is one of our largest beetles.

Distribution

Widespread.

Did you know?

Male Great diving beetles have suction pads on their front feet in order to grip the females when mating; females have a series of deep grooves running along their wing cases.