in zoology, a genus of insects belonging to the order of insecta hemiptera. The rostrum is situate on the breast; the feelers are longer than the breast; the four wings are deflected; the breast is gibbous; and the feet are of the jumping kind. There are 17 species, and the trivial names are taken from the plants which they frequent, as the chermes graminis, or grass-bug; the chermes ulmi, or elm-bug, &c.