By Katie Harris
I am always amazed to meet someone who has spent a lot of time hiking in our mountains, but has never heard of the Blue Ghosts. Perhaps it is because this eerie nighttime show takes place only for a few weeks each year, but for those who venture out when conditions are right, an unforgettable sight awaits.
The Blue Ghost, or phausis reticulata, is one of the rarest species of firefly, found only in the southern Appalachians; Western North Carolina boasts the largest population. They can only be viewed from about mid-May to mid-June, give or take a few weeks. I also need to set the matter of naming straight here: most native Southerners refer to this insect category as “lightning bugs” rather than “fireflies.” It’s a fun cultural tell when you are conversing with someone.
I remember the first time I saw the blue ghosts. I walked into the nocturnal forest along a trail, settling into my seat (also on the trail), and waited quietly with a couple of friends to see if we had picked the right spot. Our eyes needed plenty of time to adjust to the darkness. After a few minutes, I thought I saw something out of the corner of my eye– pale blue, hovering just a foot above the ground. Then another. Then another. Soon the grounds off-trail filled with quiet, steady blue lights. I felt transported to outer space, staring down at a Milky Way before me. I have yet to view a photograph or video that truly matches this experience. Your average camera or smartphone doesn’t stand a chance; don’t even try.
How have these creatures evolved so differently in comparison to their other bioluminescent family members? It comes down to mating ritual and biology. About the size of a grain of rice, the male blue ghosts have wings, but the females do not, creating a mesmerizing game of hide and seek. The females look like they are still in larva form, with transparent bodies revealing their minuscule organs. They crawl among the leaf litter, tiny but fierce predators who snack on critters several times their size, such as worms or snails.
During their short mating season, the males fly slowly over the ground, searching for a mate and emitting their steady blue glow in hopes of a response. If a female on the ground is attracted, she will emit blue light from several tiny holes in her abdomen… giving the “green light.” Or do I mean the blue light?
After mating, the female will lay about 20-30 eggs in the leaf litter. She will guard these eggs until her death. Once the mother has passed on, many of these eggs become snacks for others; only a few survive to adulthood, making their glowing presence in May all the more precious.
Dr. Jennifer Frick-Rupert of Brevard College tells a funny story about how alarmed some of the founders of Dupont State Forest were when they discovered these faintly glowing insects on the new state forest lands. They were concerned that chemicals from Dupont had somehow created a mutated version of the lightning bug, Ninja Turtle-style.
So you may be asking yourself at this point, where do I find these luminous flying rice grains? Begin by asking when. Weather and temperature are key. Light rain and warm soil bring the blue ghosts out in droves. Years of drought reduce them, as can particularly hard rains. Many people have noticed that the mating season seems to be occurring earlier and earlier, probably due to climate change’s gradual impact on soil temperature. You must stay out late for the light show as well; blue ghosts are most visible from about 9pm to 10:30pm, usually disappearing by midnight.
To know where to look, you must also know how to not further damage these special populations. Forested areas with leaf litter and a good bit of moisture are key. The females can dry out rather easily, and the leaf litter is necessary for their hunting grounds and nursery. I recommend a forest slope near a creek or drainage with plenty of forest duff and wild ferns. However, if you find yourself tramping off trail through these areas, you are likely squashing hundreds of females.
It is for this very reason – eager seekers of the blue ghost walking around off-trail in large groups – that Dupont State Forest no longer offers nightly tours from the High Falls access area. The population was noticeably diminishing each year. Blue ghosts do not repopulate quickly. Please allow these lands to recover and heal from being loved to death.
Consider how to look as well. Your eyes must be fully accustomed to darkness. Using a red light (or covering up your flashlight with red cellophane) to get to your viewing spot helps. Think of the blue ghost males, searching for 6-8 tiny pinpricks of light among the leaf litter; they appreciate a lights-off approach. Walking around until you spot a blue ghost is not the most effective technique, either. Sitting and waiting in the dark quietly for some time before moving on to a different spot brings the greater reward. Sometimes I feel as though I am staring into one of those “Magic Eye” posters when I scour the landscape for blue ghosts. They tend to appear more than be spotted. If you are on public lands, stay on the trail as much as possible.
Though Dupont no longer offers tours, blue ghosts can be found throughout these southern mountains. The Cradle of Forestry in Pisgah National Forest offers a guided experience, including a special photography tour, throughout May. You also might take an overnight in the forest, setting aside time to sit quietly in the dark, waiting to see if the blue ghosts will visit the edges of your site.
On the note of backyards, the development of forested areas and logging practices that remove the leaf litter and forest duff have greatly contributed to the reduced habitat and numbers of these beautiful insects. Most fireflies need leaf litter during their larval stages to survive, and the range of blue ghost territory is decreasing with each coming year. Dr. Jennifer Frick-Rupert wonders if these rare lightning bugs lived throughout the Southeast at one point in time. This is something to consider if you live in these southern mountains. If you happen to have a forested yard or creek nearby, allow the layers of leaf litter to settle naturally and undisturbed. You may have a quiet treasure of blue ghosts living at the base of an old tree, the edges of a small creek bank, or the undersides of hostas and ferns. There are so many ecological reasons to leave your leaves on the ground, but this may be one of the most rewarding– a blue, unwavering spark of life to greet you every spring.