Beetles: Coleoptera

One of the most important features of the beetle that makes them distinctly beetles is their elytra, the hard exoskeleton covering over their wings. Elytra have many functions, but the most important is protection for the beetle.
Some species are able to trap moisture on their wings and keep it because the elytra protects it from the heat and wind. This has allowed some species to travel to deserts, where moisture is scarce, because they can carry their own water with them. Other species can live under water because they are able to trap air in their wings and keep it under the elytra.

There are more species of beetles than species of plants! There are about 350,000 named species of beetles in the world and many more unnamed species. In the United States and Canada, there are almost 24,000 species. That’s about 30% of all insect species in North America. The families of beetles containing the most species in North America are the rove beetles (Staphylinidae, 3100 species), the weevils (Curculionidae, 2432 species), the ground beetles (Carabidae, 1700 species), the leaf beetles (Chrysomelidae, 1474 species), the scarab beetles (Scarabaeidae, 1375 species), the darkling beetles (Tenebrionidae, 1300 species), and the long-horned beetles (Cerambycidae, 1100 species).

Most beetles are either plant feeding or predaceous. Some species have different feeding habits in different stages, such as those with predaceous larvae and plant-feeding adults. Many species feed as scavengers on dead plants and animals. Other species feed on fungi or mold, and a few are parasitic on other insects or vertebrate animals.

Adult beetles range in size from 0.01 to almost 8 inches in body length, but antennae of some are much longer than their bodies. Beetles usually have hard bodies, but sometimes they are leathery or even have soft bodies. These bodies may be very smooth or very hairy. Most beetles are dark brown or black, but many are red, blue, green, purple or a combination of colors.