Lampyridae is a family of insects in the beetle order Coleoptera. They are winged beetles, and commonly called fireflies or lightning bugs for their conspicuous crepuscular use of bioluminescence to attract mates or prey. Fireflies are capable of producing a "cold light", containing no ultraviolet or infrared rays. This chemically-produced light, emitted from the lower abdomen, may be yellow, green, or pale red in colour, and has a wavelength from 510 to 670 nanometers.

There are more than 2,000 species of firefly found in temperate and tropical environments around the world. Many species can be found in marshes or in wet, wooded areas where their larvae have abundant sources of food. These larvae can also emit light and are often called "glowworms", particularly in Eurasia. In the Americas, "glow worm" also refers to the related Phengodidae.

Biology

Fireflies tend to be brown and softbodied, often with the elytra more leathery than in other beetles. Though the females of some species are similar in appearance to males, larviform females are found in many other firefly species. These females can often be distinguished from the larvae only because they have compound eyes. The most commonly known fireflies are nocturnal, though there are numerous species that are diurnal. Most diurnal species are non-luminescent, though some species that remain in shadowy areas can produce light energy.

A few days after mating, a female lays her fertilized eggs on or just below the surface of the ground. The eggs hatch 3-4 weeks later and the larvae feed until the end of the summer. The larvae are commonly called glowworms, not to be confused with the distinct beetle family Phengodidae or fly genus Arachnocampa. Lampyrid larvae have simple eyes. The term glowworm is also used for both adults and larvae of species such as Lampyris noctiluca, the common European glowworm, in which only the non-flying adult females glow brightly and the flying males glow only very weakly and intermittently.

Fireflies overwinter (some species for several years) during the larval stage. Some do this by burrowing underground, while others find places on or under the bark of trees. They emerge in the spring. After several weeks of feeding, they pupate for 1 to 2.5 weeks and emerge as adults. The larvae of most species are specialized predators and feed on other larvae, terrestrial snails, and slugs. Some are so specialized that they have grooved mandibles which deliver digestive fluids directly to their prey. The diet of adults is variable. It has been reported that some are predatory, while others find food on plant pollen and sometimes nectar.

Light production