INSECTA: COLEOPTERA--Introduction to Beetles

Photos & text by Dr. Robert Sprackland.

Beetles are insects that have the outer pair of wings form a thick protective shielding, called an elytra, over the inner flying wings. This shield may be soft and flexible, as in fireflies, or hard and brittle, as in scarab beetles. The specimens depicted here are among the prettiest species, and are often used in the manufacture of native jewelry and artifacts.

Plusiotis resplendens

Gold Beetle

The colors of some beetles are truly staggering. This beetle, which measures about 1 inch (2.5 cm), appears to be cast from gold. These are, however, the insect’s natural colors. Along with diversity of color and texture comes a great range in size, for beetles may be almost microscopic at about 1 mm, or frightening at 19 cm/8 inches.

Silversmith Beetle

Beetles represent the largest single order of animals on earth, and make up nearly half of all known insects. An explorer to Earth from another planet might well make a survey of life here and report back to his fellows that "Earth is inhabited by beetles, with a few other interesting species here and there."

Beetles may be agricultural pests or vectors for diseases, but many species are beneficial and feed on weeds or harmful insects. They are especially important in the food chain, though--most animals at least occasionally eat beetles!

Scarab Beetle

The staggering diversity of beetle species has been immortalized in a famous story. For most of the 19th and early 20th century, many people believed in "Natural Theology," that is, you could learn to understand the mind of God by studying life on earth. A bishop asked a famous British biologist, J. B. S. Haldane, what he had learned of the Creator after a lifetime of research. Haldane remarked "he had an inordinate fondness for beetles."

The name "Coleoptera" comes from Greek words meaning "hollow wings." The remarkable species shown at right has transparent wing covers with gold, bronze, and black markings. This is Aspidomorpha australasiae Spaeth (Chrysomelidae: Cassidinae), a member of the ladybug family. Photographed at Kunini, Western Province, Papua New Guinea.