Fireflies: The night light show

Firefly photo by Chris Helzer of The Nature Conservancy.
Firefly photo by Chris Helzer of The Nature Conservancy.

One of the most iconic insects found worldwide is the beautiful firefly. These bugs bring about fond memories of warm summer nights and running around attempting to catch them, but releasing them soon after of course! Whether you call them fireflies or lightning bugs, they are in the family Lampyridae which contains over 2,000 species of lightning bugs that live in temperate and tropical environments all around the world.

The glow of the firefly is produced in the lower abdomen through a chemical reaction known as bioluminescence. This light is then used to attract mates or prey, defend territory, and warn predators away. Whatever the reason, we humans get to enjoy their wonderful show throughout the warm summer months. Most likely the bugs you see are the males that fly around in search of a female. The female will wait in tall grass, trees, or shrubs to pick out the right suitor and flash a signal back (if he is lucky).

Like many insects, the firefly goes through a complicated lifecycle that involves multiple stages resulting in the adults that put on the light show. The lifecycle of the firefly starts when the female lays her eggs during summer in leaf litter or decaying plant material. The eggs hatch three to four weeks later and the larvae then feed until the end of summer. The larvae then burrow underground and hibernate through the winter until emerging in the spring to feed for several weeks. The larvae pupate for a week or two and emerge as adults to find mates and start the cycle over again.

While fireflies may seem innocent and cute, they are carnivorous predators in both their larval and adult life stages. The larvae feed on other larvae, terrestrial snails, and slugs. The adults’ food sources are not entirely known, but may include plant pollen, nectar, other adult fireflies, or nothing at all. Some species are particularly known for eating other fireflies by mimicking the flashes of the females of another species in order to attract males and devour them. However, the fireflies aren’t a tasty food source for other animals as their blood contains a chemical that makes them taste very bitter and can be poisonous to some animals.

Want more fireflies in your backyard? You can increase your chances by creating firefly habitat. When it comes time to clean up leaf litter and debris in your yard, don’t just bag it and throw it away, but rather find a place in your yard where you can spread it out to use as a compost, such as around trees and shrubs. Also, try to keep some section of your yard that has medium or tall length grass to provide breeding habitat for the adults. Finally, turn off your outside lights whenever you can! Artificial lights can really mess up the bugs trying to find the light signals of other bugs, so turning off your lights will help them to more easily find mates and create more bugs for next year.

Luckily, Kankakee Sands provides thousands of acres of these ideal habitats with very limited artificial light pollution. So come check it out on a nice night and see the extraordinary show that takes place at Kankakee Sands every night until late fall!

Source Reference:


Matthew Kennedy is a seasonal Student Conservation Association employee working as a Restoration Management Assistant at Kankakee Sands. He grew up in Cincinnati, Ohio and went to Denison University. Future plans are currently unknown, but he hopes to continue to work in the field of conservation and land management.

The Nature Conservancy’s Kankakee Sands of Indiana and Illinois is 10,000 acres of prairie and savanna habitat in Northwest Indiana and Northeast Illinois, open every day of the year for public enjoyment.  For more information visit click here or call the office at 219-285-2184.


Comments are closed.