Insect identification > Coleoptera > True Coleoptera > Fireflies

Fireflies

Family Lampyridae (fireflies, etc.). - In several ways the insects belonging here appear to be among the simplest of the beetles. Their bodies are quite soft as compared with others; the abdomen has been little reduced, seven or eight segments being perceptible, and thelarvae are quite simple and feed on small insects and other animals such as snails, either living or dead.

Only a few members of the group are often noticed except by entomologists, but those which attract attention are familiar by the light they produce at night, which has given them the name "fireflies," "lightning bugs," etc. The light is produced by specialized areas of the body, frequently at least on the underside of the abdomen near its tip. The light itself is not persistent but comes in flashes and is distinctly yellow in most cases. It is believed to be produced by the oxidation of granules in the outer layer of the luminous organ, the oxygen being the nervous system.

In some species the adult female is wingless so that its light appears as it crawls on the ground, and such individuals are often called "glowworms."

Other insects and animals also have luminous organs, but the lights they produce are probably less frequently seen than those made by lampyrids, these being widely distributed and very abundant insects.