How Do Lightning Bugs Glow in the Dark?

The lightning bug, which is more commonly referred to as the firefly, is a beetle and a member of the Lampyridae family. Unlike many other insects which have luminescent bodies lightning bugs have wings and are able to fly, although they are also able to generate light when they are in their beginning larvae stage. These insects primarily fly and produce light when it is dark.

  1. Characteristics

    • Fireflies usually vary in size from 1/4 inch to 1 inch in length and live off of a diet of earthworms, slugs, nectar, organic material and occasionally other fireflies. Fireflies have a luminescent organ on the underside of their abdomens which allows them to generate a "cold light" that varies in color from pale yellow to reddish green. This light does not contain any ultraviolet rays and has a wavelength range of 0.00051 to 0.00067 millimeters.

    Habitat

    • There are 2,000 different species of firefly, which mostly live in North America, South America and Asia. Fireflies occupy regions which have warm and temperate ecosystems and are most active during the summer seasons. These insects also prefer living in areas where there is a significant amount of moisture and humidity. When living in climates that are dry they prefer to gather in areas of the habitat which are the most moist.

    How Lightning Bugs Glow

    • In order to produce light which resembles a glow, fireflies use a light-producing organ which is located on their sixth or seventh abdomen. In this organ there is a small combination of compounds which have the ability to become oxidized, and when combined with oxygen generate light. This reaction takes place in air tubes inside the insect's abdomen that are controlled by the nervous system, and produces light that is reflected out through the insect's thin exoskeleton.

    Purpose of Glowing

    • Although many other insects use glowing as a way to bait or attract prey, fireflies use their luminescent glow mainly for non-predatory purposes. Fireflies' glows are signals to other fireflies that they desire to mate. They use this glow to produce alternative flashing signals which attract potential mates. Both male and female fireflies send signals and use species-specific patterns in order to attract members of their own species, which they transmit in short or long pattern signals.

    Other Facts

    • Firefly glows are also occasionally used by the insects as a defense mechanism to warn predators that their taste is unappetizing. Female fireflies tend to lay their eggs in the ground where larvae grow and progress into adults. In order to attack slugs and other insects which firefly larvae eat as prey while they are underground, they inject them with a fluid which has a numbing effect.