Why do fireflies glow?
Fireflies are a type of insects that are known for exhibiting a neon glow.
Fireflies, also commonly known as lightning bugs, are predominantly known for their neon glow. Scientifically, fireflies belong to the Lampyridae family of insects in the beetle order Coleoptera. Essentially, they are winged beetles, who happen to glow. The glow is actually called bioluminescence, and serves a variety of purposes.
The bioluminescence is a cold light that has no infrared or ultraviolet frequencies. However, it is always between the wavelengths of 510 to 670 nanometers. While, most people associate neon green with the bioluminescence, it can actually be yellow, green, or pale red. This mainly depends on the species of the fireflies.
There are approximately 2,000 different species of fireflies. They are mainly found in temperate and tropical environments, often residing in marshes or in wet, wooded areas. Here, their larvae tend to have abundant sources of food. Depending on the species, the larvae often emit a glow, and are hence called ‘glowworms.’
In fact, it is actually the abdomen on the fireflies that exhibits bioluminescence. Fireflies contain a chemical in their abdomen called luciferin. When luciferin combines with oxygen and with an enzyme called luciferase, the ensuing chemical reaction causes their abdomen to light up.
The main reason behind the fireflies’ glow is to attract mates. In the evening, when the fireflies start flying around, they are actually the males flashing off for the ladies. The firefly can turn that light on and off to make a signal. The females are usually resting in the grass. If a female likes the flashing patterns of a male, she will flash him in return.
However, the glow is also used to hunt for prey. Some types of their prey are attracted to the glow of the firefly, and when they come close enough, they become easy pickings. At times, the female may use the glow to attract a male, but instead of mating with him, she ends up eating him.
Furthermore, the glow also helps fireflies deter predators. The fireflies are filled with chemicals called lucibufagins, which apparently have a very horrible taste. Once a predator eats a glowing firefly and realizes how bad it tastes, he associates the glow of the firefly with the horrid taste. Hence, it remembers not to eat something else that glows.