The beetles constitute the largest insect order. They have colonized virtually every terrestrial and freshwater habitat, and display an enormous diversity in shape and lifestyle.

Most beetles have a hard exoskeleton, and the significant trait of the group is the fore wings, which are modified to a pair of hard elytra which in rest form a protective shield over the abdomen. The hind wings are usually functional, and are folded together underneath the elytra when not in use. Beetles have chewing mouthparts, usually well developed compound eyes, and antennae of very diverse shape. The first thoracic segment forms a strong shield (pronotum) in front of the elytra. The two rear are fused with the abdomen, and are completely covered by the elytra dorsally, except for a small triangle (the scutellum) at the meeting point between the elytra and the pronotum. Beetles have complete metamorphosis, and the larvae, like the imagines, display an enormous diversity in shape and way of life.