Each insect species adult has a specific name, whether it be a butterfly, beetle, wasp or grasshopper. When referring to mature insects in general, adult is the proper name to use.
Insects are invertebrates within the arthropod phylum. All adult insects have a rigid exoskeleton, three pairs of jointed legs and three body sections. The body sections of insects include the head, thorax and abdomen. The legs and the wings of adult insects are attached to the thorax. Insects all lay eggs and enter into either complete or incomplete metamorphosis depending upon the species. In complete metamorphosis, the babies are called larvae. In incomplete metamorphosis, the babies are called nymphs, and look like miniature adults.