Photo by W. P. Dando, F.Z.S., Regent's Park.
GREAT BROWN WATER-BEETLE (MALE).
A large olive-brown species, about an inch in length, and nearly half as broad. The wing-cases of the female are grooved.
This beetle must not be confounded with the still larger Black Water-Beetle, which belongs to another group. This fine insect, which is not predaceous in the perfect state, is locally plentiful in ditches, and is in great request as an inmate of the freshwater aquarium. The hind limbs are not modified for swimming purposes.
Next in order come the Cocktails, so called from their curious habit of turning up the end of the body when alarmed. To this group belong most of the tiny "flies" which cause such severe pain when they find their way into the eyes. Some species, however, attain to a considerable size, the well-known Devil's Coach-Horse being fully an inch in length. The great majority are scavengers, being found in carrion, manure, and decaying vegetable matter. A few, however, are lodgers in the nests of ants, by whom they appear to be regarded as pets and treated with the utmost kindness.
Photo by W. P. Dando, F.Z.S., Regent's Park.
BLACK WATER-BEETLE.
A shining black species, longer, narrower, and more convex than the Great Brown Water-beetle.