What is a Firefly?
Despite its name, fireflies are not flies at all! Instead, they have hardened forewings called elytra, and belong to the most abundant order of insects, Coleoptera, or the beetles. The firefly family is called Lampyridae, and many of them can be easily identified by their bioluminescent, or glowing, abdominal region.
Biology of a Firefly
There are over 2000 known species found in temperate an tropical climates across the globe. They live in marshes, or wet, wooded areas where it is suitable for females to lay eggs, and have plenty of food source available for the larvae.
Firefly larvae are carnivorous. They live in moist soil, feeding on other larvae, terrestrial snails, worms and slugs. The adults may also be predatory. However, many feed on plant pollen or nectar, while some lack mouthparts as adults so they do not feed at all.
How They Glow & Why
The glow emitted by fireflies is called ‘cold light’, meaning it produces almost no heat. A firefly inhales oxygen, and this reacts with the chemical luciferin in its light emitting organ, to produce light. This chemical reaction is called ‘bioluminescence’. The colours produced mostly range from oranges to yellows and greens, depending on the species.
The glow is used as a visual signal to attract mates. Different flashing patterns can carry different messages, and patterns vary across different species. Interestingly, firefly eggs and larvae of some species can produce light too! This led scientists to believe that they use bioluminescence as a warning signal as well, to communicate with predators that they are not palatable.