Many fireflies protect themselves from predators with chemicals called lucibufagins. Both species, however, occur over wide geographic ranges, and it might be possible to see them in other, less congested places. These displays are spectacular, and the crush of folks wanting to see them at the most famous locations has made it necessary to conduct a lottery for permission to view them. In both these species, scientists think the males synchronize so everyone has a chance to look for females, and for females to signal males. In North America, the two most famous species that do this are the Photinus carolinus of the Appalachian Mountains, including in Great Smoky Mountains National Park, and the Photuris frontalis that light up places like Congaree National Park in South Carolina. While most male fireflies do their own thing and flash independently of other males of the same species, there are those that synchronize their flashes when there are many others around. Play Video Some Tennessee fireflies put on a synchronized show. Firefly light communication can get much more complicated some species have multiple signaling systems, and some might use their light organs for other purposes. Some species may “call” for many hours a night, while others flash for only 20 minutes or so right at dusk. If she sees a fellow she likes, she waits two seconds before making a half second flash of her own at the third second. Every five seconds or so, he makes a one-second flash as he flies in the shape of a “J.” The female Photinus pyralis sits in low vegetation. A male flies at dusk about 3 feet off the ground. If everything goes right, they mate.Ī good example is Photinus pyralis, a common backyard species often called the Big Dipper. Then the two reciprocally signal as the male flies down to her. When a female sees one making her species’ signal – and doing it well – she flashes back with a species-appropriate flash of her own. The females are sitting on the ground or in vegetation, watching for males. In most North American species, the males fly around at the right height, in the right habitat and at the right time of night for their species, and flash a signal unique to their kind. Interestingly, not all fireflies produce light there are several species that are day-flying and apparently rely on the odors of pheromones to find each other.Įach firefly species has its own signaling system.

Entomologists think they control their flashing by regulating how much oxygen goes to their light-producing organs.įireflies probably originally evolved the ability to light up as a way to ward off predators, but now they mostly use this ability to find mates. Bioluminescent beetlesįireflies produce light in special organs in their abdomens by combining a chemical called luciferin, enzymes called luciferases, oxygen and the fuel for cellular work, ATP.

Fireflies are found widely across North America, including many places in the west, but they are most abundant and diverse in the eastern half of the continent, from Florida to southern Canada.

Recently, I’ve been trying to understand the diversity and ecology of fireflies in my home state of North Carolina. I’m an entomologist who does research on, and teaches about, the ecology and biology of insects. The most dramatic aspect of their biology is that they can produce light this ability in a living organism, called bioluminescence, is relatively rare. They’re soft-winged beetles, related to click beetles and others. If you are in good firefly habitat, soon there are dozens, or even hundreds, of the insects flying about, flashing their mysterious signals.įireflies – alternatively known as lightning bugs in much of the United States – are neither flies nor bugs. But you stare in the direction of the flicker of light and there it is again – the first firefly of the evening. You might not really be sure you saw what you think you saw when the first one shows up. Clyde Sorenson, North Carolina State University

Synchronized lightning bugs