Beetles, Pacific Northwest
Most species of ground beetles found on Vancouver Island are dull brown or black in color, with long parallel grooves and ridges on the back of their abdomen which is actually their hardened front pair of wings. They have long legs which allow them to move quickly along the ground in search of prey.
European ground beetles are easily distinguished from the others because they are about 2.5 to 4 cm long, making them the largest ground beetles on the island and their upper thorax and elytra are metallic purple or coppery in color. The elytra each have 3 rows of dimples running along the ridges.
Like most ground beetles, European ground beetles are active at night, and during the day they can often be found resting under leaves or other objects on the ground. This species is often found in habitats associated with humans, such as gardens and near buildings. You are likely to find European ground beetles just about anywhere on Vancouver Island, in forests, fields or around your home. They are often found in large numbers in a single area.
Adult beetles spend the winter hibernating in the soil or leaf litter, under bark or stones. They mate in the spring, and females lay their eggs in the soil. Egg and larval stages are completed through the spring and summer, and the new adults appear in late summer to early autumn. Individuals may live for two years. European ground beetles have large mandibles which they use to feed on soft-bodied prey like slugs, earthworms, and caterpillars; the larval beetles are also fierce predators. They are good to have in your garden! Like many ground beetles, this species can emit a very smelly (but otherwise harmless) substance from glands in its abdomen if you pick it up. European ground beetles have nonfunctional hind wings and cannot fly.