Which order is beetles, characterized by chewing mouthparts and elytra that cover the wings?

• A. Coleoptera
• B. Diptera
• C. Lepidoptera
• D. Hymenoptera

Answer: (A)

Beetles are defined by chewing mouthparts and forewings that are hardened into a protective sheath, called elytra, which cover the hind wings when the insect is at rest. That combination—strong, chewing jaws and elytra covering the wings—significantly distinguishes this group, so the insect described fits this order best. The elytra not only protect the delicate flight wings but also the abdomen in many species, and the name of the group comes from the Greek for “sheath-winged.”

Other insect groups don’t share this exact feature set. Diptera have only one pair of wings and a pair of balancing structures called halteres, not elytra. Lepidoptera carry wings that are covered with scales and typically have mouthparts adapted for sipping liquids, not the robust chewing type. Hymenoptera possess two pairs of wings that are usually membranous and not hardened into sheaths, with mouthparts that can be chewing or piercing-sucking, depending on the species. These differences help separate beetles from those other orders.