For a short time at the end of June, the cool yellow-green light-flashes of fireflies can be seen after dusk and and the onset of darkness. Our garden is a good place to spot them. In the evening, they hover over the plants or sit near the ground. The most common species in our city has the scientific name Photinus pyralis. As you can see on the photo below, fireflies are not flies at all, but beetles, complete with sturdy elytra that protect the wings when the firefly is not in the air.
The cool thing (literally) about fireflies is that they can produce light. This is done by a chemical process during which the protein luciferin reacts with the enzyme luciferase. Both chemicals are stored in an organ on their belly that is fittingly called the lantern.
Why the glow? Fireflies use light to find a mate. Males flash a signal during flight and wait for a female on the ground to respond with her flash. The sequence and color of the light tells them that they belong to the same species. Males and females keep doing this until they find each other and mate. The life of adult fire flies is short: they don’t even bother to eat and die after the females have laid their eggs.
All of this happens only at the beginning of summer. The rest of the year, the new generation of fireflies lives as carnivorous, flightless larvae near the ground. In winter, these larvae burrow into the soil and pupate. When metamorphosis is completed the following June, adult beetles emerge and begin their light show.
I made a little movie starring fireflies from our garden:
If you want to see these natural fireworks for yourself, look near bushes and trees at around 8pm. I am sure the fireflies are there.