Great Diving Beetle

Dytiscus marginalis

  1. Wildlife
  2. Invertebrates
  3. Beetles
  4. Great Diving Beetle


The Great Diving Beetle is a very large diving beetle. Great Diving Beetles are voracious predators in ponds, feeding on many 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. Great Diving Beetles are common in ponds and slow-moving water. They can be spotted coming to the surface, pointing the tip of their abdomen out of the water to replenish the air supply stored beneath the wing cases. The larvae use damp soil by the edge of the water to pupate in.

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.

Where to find it


When to find it

  • January
  • February
  • March
  • April
  • May
  • June
  • July
  • August
  • September
  • October
  • November
  • December

How can people help

Human activity, including the drainage of land for agriculture and the loss of ponds through development, has resulted in the disappearance of many wetlands. The Wildlife Trusts are working closely with planners, developers and farmers to ensure our wetlands are protected. You can help too: encourage all kinds of insects from Great Diving Beetles to dragonflies into your garden by having a wildlife-friendly pond. In turn, they'll provide vital food for other creatures such as frogs and toads. To find out more about encouraging wildlife into your garden, visit our Wild About Gardens website: a joint initiative with the RHS, there's plenty of facts and tips to get you started.

Species information

Common name
Great Diving Beetle
Latin name
Dytiscus marginalis
Length: 3cm
Conservation status