Beetles (Coleoptera)

This group gathers Insects subcategory members belonging to the order Coleoptera, the beetles, the single largest order in the entire animal kingdom by number of described species, defined by a hardened, shell-like pair of forewings, the elytra, that meet in a straight line down the back and protect a functional pair of flight wings folded beneath. It spans the ground beetles, fast-running predators found under stones and leaf litter worldwide, the scarabs, including the dung beetles and the enormous rhinoceros and Hercules beetles, the ladybirds, familiar aphid-eating predators, the fireflies, whose bioluminescent courtship flashes are produced by a light-emitting chemical reaction, the weevils, recognized by an elongated snout, the click beetles, capable of snapping their body straight with an audible click to right themselves or escape a predator, and destructive pest species such as the boll weevil and the mountain pine beetle.