Lesser silver water beetle  (Hydrochara caraboides)

This species is known only from the UK, and was widely distributed during the 19th century. However, since 1970, it had only been recorded in eleven 10km squares, with the only known breeding population in the Somerset Levels. Then, in 1990, an adult beetle was found in a pond in Cheshire. Since then, larvae have been found in several other ponds in the county as well as former sites on the Somerset Levels.

The adult lesser silver water beetle is found in still, weedy ditches and ponds in peat-rich areas. It seems to prefer deep water where there is little chance for the peat to dry out, and places subject to piecemeal disturbance. Recent research, however, suggests that the eggs and larvae are found in shallow, often temporary, ditches with overhanging tree cover.