If you are fortunate enough to live near the southern Appalachian Mountains, you may see ghosts this time of year. If you are really lucky, you may see hundreds of ghosts, for at the edge and up into the Blue Ridge Escarpment lives a unique insect known as the blue ghost firefly, Phausis reticulata.
Blue ghost fireflies are neat beetles in that they are native in the mountainous areas of the Upstate. Unlike their quick flashing cousins (there are over 125 firefly species in North America!), they glow for 30 or 40 seconds every time they light up. Both the males and females produce a bluish-greenish glow, but only the males can fly. Being small, the females look like large grains of glowing rice. With their “girlfriends” stuck on the earth, the males fly slowly close to the ground. In concert, the slow glowing swirl of the hundreds of males flying over their glowing girlfriends during their April/May mating flight is magical. It truly makes the forest look enchanted, but the show is short-lived, only lasting a couple of weeks each spring.
Like most firefly species, the population of blue ghost fireflies has probably decreased over the last thirty years based on accounts by long-term residents along the Blue Ridge Escarpment. The reason for declining numbers may be due to multiple reasons, including loss of suitable habitat to development, years of drought, and light pollution impacting mating. In addition, over-use of insecticides over wide areas has probably also had an impact.
So, this spring and summer, if you want to encourage blue ghosts or any other firefly species around your property, avoid using broad-spectrum insecticide applications in your yard. Keep a diverse habitat. Fireflies are predators that feed on other bugs. They like wooded areas with native plants, especially along creeks, streams, ponds, and lakes. Finally, one of the easiest forms of pollution you can remediate is light pollution. Turn off your outdoor flood lights as much as possible. If you do, you may be rewarded by the magic of fireflies, and if you live in the right areas along the mountains, you may even see some blue ghosts.
For more information about blue ghost fireflies, consider viewing the video interview by Katlyn Mobley of Dr. Jennifer Frick-Ruppert at Brevard College in North Carolina. Dr. Frick-Ruppert is a graduate of Clemson University (BS & PhD) and an expert on blue ghost fireflies: https://realdigitalproductions.com/blue-ghost-fireflies/