Summer nights become quite magical after the sun goes down and fireflies begin to fill our backyards with brilliant light displays. Sometimes called a lightning bug, sometimes a glow bug, and in our area the name firefly is most common, but did you know that these spectacular creatures are not flies at all. They are beetles, and there are approximately 2,000 different species around the world.
What sets them apart from other beetles is a light-making organ located just below their abdomen. To make light, the fireflies take in oxygen, which mixes with a natural substance found in the cells of this organ, causing a chemical reaction to occur. The whole process is called bioluminescence. They use bioluminescence to communicate with each other and to find potential mates, each species has their own unique light pattern. Unlike a light bulb, when a firefly lights up, it produces almost no heat.
And adult fireflies aren’t the only ones that glow. In some species, the larvae and even the eggs emit light. Firefly eggs have been observed to flash in response to stimulus such as gentle tapping or vibrations.
There are two areas in the world where fireflies all flash at the same time, rather than the individual flickerings that we see in our area. This simultaneous flashing happens only in the Great Smoky Mountains National Park in Tennessee, USA, and in southeast Asia.
Outdoor lights prevent fireflies from seeing each other’s flashes, so they have a hard time finding mates. Other potential threats to these amazing beetles include habitat loss, pesticide use and climate change. So, turn off your lights at night during firefly season to ensure you have a spectacular display this summer!