What characteristic describes adult beetles?

Adult beetles are characterized by having chewing mouthparts and hard, leathery wings. This anatomical structure is distinctive to beetles, which belong to the order Coleoptera. The hard wings, known as elytra, serve a protective function, shielding the delicate hind wings and abdomen. Chewing mouthparts enable beetles to feed on a variety of foods, including plant material, other insects, and decaying organic matter, making them versatile and successful in diverse habitats.

Other options do not accurately reflect the common characteristics of adult beetles. For instance, soft-bodied insects with long antennae are more typical of other insect groups, such as some types of caterpillars or aphids. Small and transparent wings may describe certain other insects but not the robust wings of beetles. The characteristics of being free-moving with long legs do not specifically apply to beetles, as their body structure and movement are distinctively adapted to their lifestyle and feeding habits.