Lightning Bugs

Lightning Bugs

Lightning Bugs and Fireflies (Lampyridae)

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 produce a “cold light”, with no infrared or ultraviolet frequencies. This chemically-produced light from the lower abdomen may be yellow, green, or pale-red, with wavelengths from 510 to 670 nanometers.


There are 2,000 species of fireflies found in temperate and tropical environments. Many are in marshes or in wet, wooded areas where their larvae have abundant sources of food. These larvae emit light and are often called “glowworms”, in particular, in Eurasia. In the Americas, “glow worm” also refers to the related Phengodidae.


Fireflies, also known as glow worms, tend to be brown and soft-bodied, 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.

What causes the lightning bug to glow?

Light production in fireflies is due to a type of chemical reaction called bioluminescence. This process occurs in specialized light-emitting organs, usually on a firefly’s lower abdomen. The enzyme luciferase acts on the luciferin, in the presence of magnesium ions, ATP, and oxygen to produce light. Genes coding for these substances have been inserted into many different organisms (see Luciferase – Applications). Firefly luciferase is used in forensics, and the enzyme has medical uses — in particular, for detecting the presence of ATP or magnesium. It has been speculated that Baroque painter Caravaggio may have prepared his canvases with a powder of dried fireflies to create a photosensitive surface on which he projected the image to be painted.


All fireflies glow as larvae. Bioluminescence serves a different function in lampyrid larvae than it does in adults. It appears to be a warning signal to predators since many firefly larvae contain chemicals that are distasteful or toxic.

Why do lightning bugs and fireflies glow?

It is thought that light in adult beetles was originally used for similar warning purposes but evolved for use in mate selection. Now fireflies are a classic example of an organism that uses bioluminescence for sexual selection. They have evolved a variety of ways to communicate with mates in courtships: steady glow, flashing, as well as the use of chemical signals unrelated to photic systems.


Some species, especially lightning bugs of the genera Photinus, Photuris, and Pyractomena, are distinguished by the unique courtship flash patterns emitted by flying males in search of females. In general, females of the Photinus genus do not fly, but do give a flash response to males of their own species.

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Get rid of pests and keep them away. Call Atkins for professional residential or commercial pest control services tailored to your needs. We offer seasonal services or one-time solutions. Either way, you'll get professional results.
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