As early summer visitors are increasingly flocking to the area to see the phenomenon of synchronous fireflies, researchers are hoping to learn more about how and why these beetles produce such amazing light shows.
It may well be the most beautiful mating ritual on the planet.
Deep in the Great Smoky Mountains, from the edge of Lake Santeetlah near Joyce Kilmer Forest, male fireflies hover along mountainside and open areas. At dusk, there will be a light blinking here and there. Then as more fireflies join in, their lights blink together in unison. By 10 p.m., whole glades and hillsides flash like massive strings of Christmas lights blinking in unison.
It’s an experience that inspires nothing short of awe.
Scientists aren’t sure why fireflies coordinate these brilliant light shows, but the spectacle seems to center around mating. In order to attract mates, different species of fireflies produce different light patterns. Some give off a steady bluish-green glow, others a series of bright yellow Morse Code blinks, and still others a tiny, double-blink beacon in the soil. It’s the Photinus carolinus — the synchronous firefly — is starting to attract the curious to Robbinsville in early June.
Fireflies, or lightning bugs as they are also called, are technically beetles. Contrary to their name, not all fireflies light up at night (some cruise around by day) and not all have wings (some females remain ground-bound). Generally the males outnumber the females and appear to have larger bodies. When it comes to signaling with their abdomen lanterns, fireflies use different colors and frequencies depending on the species.
The male Photinus fireflies blink about four to eight times in the air, then wait about six seconds for the females on the ground to return a double-blink response. Once the male locates a female, he lands and mates on the ground. An adult female will produce about 50 to 80 eggs at a time and lay them in the ground (even the eggs glow). After about three weeks, the eggs hatch and the little glow-worms will live in the soil for about two years before they undergo a metamorphosis, sprout wings and develop a shell over their backs.
The synchronous firefly show, which researchers have identified as a rare form of simultaneous bioluminescence, exists in high-elevation wetland areas in Southern Appalachian forests as well as in China and Thailand.
Generally, synchronous fireflies have been reported in wetland areas in high altitudes above 2,000 feet, though recent sightings claim they exist in lower altitudes and other regions previously not thought to be “normal” firefly habitats — coastal Georgia, for example.
According to the Web site of the Great Smoky Mountains National Park, about 20 species of fireflies have been found in the park. (Some 126 species of fireflies exist throughout North America.) About eight species in the Park don’t produce light; they cruise around during the day. The other 12 have powers of illumination and various blinking patterns.