How Does The Carnivorous Diving Beetle Reproduce?

Two carnivorous beetles mate after an elaborate courtship during which the male swims persistently round his chosen mate and strokes her gently with his antennae. Male carnivorous beetles are different from females because they have much larger front legs, which have a row of suckers on the underside. As soon as a female agrees to mate, the male climbs onto her back and clings to her grooved wing case using these suckers, which secrete a sticky fluid for extra grip.

Once mating has taken place, the female uses a special egg laying tube that is like a small serrated knife to puncture the leaves and stems of underwater plants. Through these incisions, she inserts the eggs so that they have a sheltered and safe place to develop.

The eggs are camouflaged to look like plant buds and they develop into long tapering larvae. The larvae are free swimming and live in the same habitat as the beetles but prefer slightly shallower water. The larvae emerge from the water and build a chamber on a muddy bank where they go through the pupal stage to become an adult beetle.