Photo by: Spencer Black

Spencer Black

Rare Blue Ghost Fireflies Only Glow in One Part of North America

By: Annie Hartman

These insects emit a glow a yellow-green hue.

August 01, 2019

For those who grew up around them, fireflies (aka lightning bugs) spark childhood memories of hours spent desperately trying to clasp them in our hands or stuff them in a jar. Those critters, by and large, glow a yellow-green hue. But in a few rare regions of North Carolina, as the weather starts to warm up in the Appalachian mountains, blue ghost fireflies begin to emit a color firefly lovers aren't used to seeing.

Photo by: Spencer Black

Spencer Black

This Little Light of Mine

For just two to four weeks a year, blue ghost fireflies make an appearance around Asheville, North Carolina. This rare type of firefly only glows during mating season, which begins in the late spring or early summer. That's when they show off their unique blue-white hues to attract a mate.

The color isn't the only unusual quality about these otherworldly insects. While other fireflies flash on and off like a warning light, blue ghosts glow for up to a minute at a time. The males can fly, painting streaks of bluish-white light through the forest. The females don't fly — despite reaching sexual maturity, they never change from their wingless larval form. As a result, they're left to crawl up on leaves and foliage just a short distance from the forest floor, then sit still and glow to help males find them.

Fireflies are bioluminescent, which means they produce their own light. According to researchers from Harvard Medical School, the light comes from the mixture of oxygen, a pigment called luciferin, an enzyme called luciferase, and an energy-providing chemical called adenosine triphosphate (ATP). Uric acid crystals in the light-producing cells act as the reflective layer that helps the light shine. But nobody is exactly sure why these fireflies differ so much from other subspecies.

The "blue" in their name makes sense, but what about the "ghost" part? According to Appalachian legend, the glowing blue fireflies are said to be ghosts of Confederate soldiers, as many soldiers lost their lives in the region where the fireflies appear.

How to See Them

Since these fireflies are crazy about moist forest floors, people walking the trails in the area would be likely to crush them. Plus, lights from phones and flashlights might also affect the fireflies' communication. That's why when mating season comes around, some state parks close many of their trails to preserve these unique creatures.

But don't worry: If you're dying to see them — along with the whopping 18 other firefly subspecies in the area — there are a number of ways to legally take a peek. If you do plan a visit, take a few precautions: load up your flashlight with Duracell batteries and cover the light with red or blue cellophane to retain your night vision (or just grab a red-tinted headlamp like this one). Once you reach the designated area, turn off your flashlight and take it all in.

This article first appeared on Curiosity.com.

Next Up

The “Lungs of Our Planet” are Under Threat

World Rainforest Day is June 22, bringing awareness and action to save these precious ecosystems. But if the current rate of deforestation continues, will there be any rainforests in 100 years?

Wombats: The Furry Heroes of the Australian Wildfires

Wombats dug craters which tapped into deep-flowing water, providing vital resources to fauna and fellow animals.

New Study from Brazil Makes a Huge Splash in Manta Ray Conservation

One batoid (the skates and rays) that needs no introduction are the manta rays. With 20-ft wingspans, these plankton-loving filter feeders can glide through bright blue oceans as if soaring effortlessly across a cloudless sky.

Octopuses Don't Have Tentacles!

What exactly do these cephalopods have then?

Bigger, Badder, Fatter: Fat Bear Week 2019 is Here

It's time for the bears to pack on the salmon and prepare for winter hibernation, but first they must compete in a battle of the fattest: Fat Bear Week.

Bei Bei Says Bye Bye - National Zoo’s Giant Panda Prepares for Move to China

After four years of delighting individuals and families in the United States, giant panda Bei Bei is ready to bid farewell and embark on the next stage of his life in China.

Living in Harmony with Snow Leopards

The Himalayas is home to the snow leopard, one of the most beautiful big cats in the world. But numbers are dwindling as snow leopards struggle to find prey in the changing landscape. Learn what this small village is doing to help save the cats while living in harmony with the big cats.

How the Mediterranean Became a Corridor of Death for Birds

Across the world, the bird population is thinning due to illegal poaching and habitat loss, especially in Europe and Africa during migratory seasons. Conservation groups globally are trying to protect our nearly extinct feathered creatures.

Saving the Black Bears of the West

Black bears are North America’s most familiar bears. One non-profit is working to reduce state-approved hunting programs in the American West to save the black bears.

St. Croix Locals Band Together to Save Their Island's Turtles

Since 1977, scientists have been monitoring leatherback turtle populations in order to help protect the species.