What do Lightning Bugs Eat? Welcoming Fireflies to Your Garden

As a kid, I remember the magic of seeing clouds of fireflies on a warm summer night. Nowadays, I get excited if I see one or two floating around our yard. Also called lightning bugs, these special little insects are an important indicator of environmental health. And they’re also good for our gardens. So, how does a gardener support them? What do lightning bugs eat? What’s the difference between lightning bugs and fireflies? What about glow-worms? (Are those even a thing?!) It’s easy to find confusing or conflicting information about these bioluminescent marvels online. In this article, I’m going to share some tips on what these special creatures need to survive, how we can help sustain them, and why we should make the effort.

Earth has more than 2,000 species of fireflies in all. You’ll find them nearly everywhere—except for the Antarctic. Commonly known as lightning bugs or fireflies, these insects in the Lampyridae family use flashes of light as mating signals. Fireflies in the genus Photuris and those in Photinus are two common types.

Of course, there are many more kinds of fireflies ranging in size and featuring different flash colors and configurations. Despite their differences, they do have something in common—namely the mechanism behind their ability to light themselves up. It’s a little complicated, but here are the basics. Essentially, a chemical reaction takes place within specialized light organs within each insect’s abdomen. Among the chief chemicals involved is a molecule known as luciferin, an enzyme called luciferase, oxygen, and adenosine triphosphate (ATP). When combined, this complex stew creates the lightning bug’s signature glow.