By Adam Edge and Paula Musto
Fireflies are some of the most fascinating creatures on Planet Earth. Witnessing their whimsical lights flickering in the dark is a magical experience cherished by adults and children alike. While many may think that fireflies are nothing more than a pleasant viewing experience on summer nights, there is a lot more to these intriguing insects.
What are commonly called fireflies or lightning bugs are actually flying, soft-bodied beetles with abdomens that glow intermittently. A chemical reaction within their internal organs allows them to produce light with almost no heat, a phenomenon called bioluminescence. There are more than 2,000 species of these bioluminescent beetles in the world.
Firefly light is usually intermittent and flashes in patterns unique to each species. It’s their way of talking to each other to find a mate. But lighting up may also serve as a defense mechanism, signaling a warning that the insect has unappetizing taste making it unpalatable to would-be predators.
Most of us are accustomed to seeing the Common Eastern Firefly, a species often found in our backyards. But there are many different species in Western North Carolina that are less frequently seen. For those lucky enough to witness them, synchronous fireflies flash in unison, creating a spectacular light show. Each summer, a number of regional venues, including Grandfather Mountain, hold special events for a limited number of ticket holders to view the spectacle. Thousands vie for the opportunity to see this dazzling display.
“The light show that the synchronous fireflies put on is actually a mating ritual,” says John Caveny, director of conservation and education for Grandfather Mountain. “There is a call and response going on between the males and females of the species. The males are flying around, and the females are in the grass. One group of males will emit synchronous flashing patterns as they try to find receptive females, and the females will respond with a double pulse answer.”
Fireflies aren’t endangered, but wildlife conservationists are concerned. In recent years, fewer of the insects have been spotted during the summer. Pesticide use and loss of habitat have likely impacted the population as has artificial light pollution. Too much nighttime light can be harmful to many species of wildlife, affecting their migration patterns and hunting abilities. For fireflies, light pollution, even from decorative garden solar lighting, interferes with their attempts to signal each other.
Fireflies can serve as an important indicator species to gauge the amount of light pollution in an area, according to Caveny. Light pollution is a direct result of urbanization—as more and more houses, buildings and roads are constructed, greater amounts of light are broadcast into the night. This can confuse many nocturnal species—including fireflies—making it difficult for them to find and signal to their mates.
“You will see more fireflies in areas that are darker than others,” Caveny says. “If fewer and fewer fireflies are spotted in an area, it likely means that the light pollution is driving them away.”
There are a number of things people can do to help support fireflies, including turning off outdoor lights and shutting blinds at night, minimizing the number of pesticides in yards and leaving a buffer between woods and yards when mowing. “If enough people practice these suggestions,” Caveny says, “the lives of many fireflies will be protected.”
If you are invested in the future of these magical insects, there is one more thing you can do. Help spread the word that fireflies need our support. It’s important that these magical insects are still around for future generations to observe and enjoy.
Adam Edge is a firefly enthusiast who is attending the University of North Carolina at Chapel Hill this fall and majoring in environmental science. Paula Musto is a writer and volunteer for Appalachian Wild, a nonprofit whose mission is to help injured or orphaned wildlife, support WNC’s wildlife rehabilitation network and provide wildlife conservation education. To help save wildlife, donate and learn more, visit AppalachianWild.org.