Nothing embodies the magic of the outdoors more than the dancing fairy lights of fireflies.
By Wendee Holtcamp
The firefly's flame
Is something for which science has no name
I can think of nothing eerier
Than flying around with an unidentified glow on a person's posteerier.
- Ogden Nash
Along the banks of the briskly flowing Colorado River, 11 boys and girls and half as many adults have set up camp. For many of these fifth graders from Houston's Holy Trinity Episcopal School, this is the first tent camping experience of their lives, with all its associated fears and joys – setting up a tent, swimming in waterholes with "gross" algae, skipping stones, taking a night hike, roasting marshmallows around the campfire. In nature, kids can overcome fears, see things in new ways, and witness phenomena they've only seen before in books. Magic lives outdoors, and in a trip filled with a dozen new thrills, nothing embodies that more than seeing the dancing fairy lights of fireflies for the first time.
The orange-yellow lights started blinking around dusk. It was May, early in the season for fireflies, which come out during summer nights. "Look! Fireflies!" I said when I noticed the tiny glittering lights and pointed them out to the kids.
"It was really cool how they'd go on and off all at once," said MacKenzie, who observed that the fireflies stopped flashing as she approached. True synchronized flashing occurs in fireflies in Thailand and Malaysia, where thousands of fireflies gather along waterways, blinking like Christmas lights. Some North American species can be induced to flash synchronously and some species may flash all at once to deter predators, which may be how the fireflies perceive the excited children.
Imagine what people thought of fireflies before electricity! Ancient Mayas believed that fireflies carried the light of stars. In Japanese culture, fireflies contain the souls of soldiers who have perished in battle and have represented passionate love in Japanese poetry since the 8th century. More than 2,000 species of fireflies live throughout the world, with the greatest diversity in the tropics, particularly Asia. The United States has approximately 175 species, mostly in the east, and Texas has 36 known species. The commonly seen Big Dippers make a J as they flash, starting at the lower hook and moving up and right.
My son Sam and his friend Brent put a few of the lightning bugs in empty plastic bottles. "We wanted to see if we could catch enough to light up our tent," Sam said. They were not the first with this creative idea. The Japanese used to make lanterns filled with fireflies.
Fireflies flash for two main reasons: to attract mates and to warn predators that they don't taste good. Poisonous insects, frogs and other creatures active during the day may have red or other bright colors to warn predators not to eat them, but colors don't do much good at night. The firefly's solution? Glow in the dark!
A firefly's glowing/flashing organ is called a lantern. Once fireflies evolved bioluminescence to deter predators, some species co-opted the glowing for a second purpose: attracting mates. Some fireflies that flash contain nasty-tasting chemicals to deter predators. The light-producing chemical reaction is very energy-efficient, with little heat given off as a waste product – unlike incandescent light bulbs, which exude 90 percent of their energy burned as heat. The firefly chemical reaction is so unique that medical scientists use this glow-producing chemical reaction to reveal bacterial and viral infections, search for life in outer space and destroy cancer cells.
For some fireflies, their glowing serves as their downfall – and not because boys and girls catch them. According to University of Georgia professor Kathrin Stanger-Hall, "femmes fatales" lure in fireflies of a smaller species with their flashing lights and then ... eat them! The femmes fatales not only get a meal, they also absorb the lucibufagins (toxic defensive steroids) that protect against predators without having to produce the chemical themselves.
"With all the different species of fireflies, how do they know that they're closing in on the right species and not a femme fatale?" says Stanger-Hall about her research. She studied fireflies in several Texas parks before moving to Georgia, and explains that firefly species that blink at dusk tend to have orange-yellow light, whereas those that come out later at night tend to have green light. She often found several firefly species within relatively close proximity to one another in Texas parks. Not all adult fireflies glow.
Brent says that his grandmother had told him how hundreds of fireflies would twinkle during summer nights at her home in Louisiana, but he'd never seen them until he went camping here in Colorado Bend State Park. "They were not what I expected," he said. "I thought it would be a bug with light through its whole body, but it was a fairly large bug with a light on its backside."
It turns out fireflies are not "bugs" at all, since, scientifically speaking, "true bugs" include things like assassin bugs, stink bugs and bed bugs. Nor are fireflies flies. Fireflies are actually beetles. Firefly larvae, known as glowworms, flattened worm-like creatures, live up to two years feeding on slugs, worms and other slimy things in moist leaf litter. Adult fireflies emerge in spring and summer.
British evolutionary biologist J.B.S. Haldane frequently remarked, "If one could conclude as to the nature of the Creator from a study of creation, it would appear that God has an inordinate fondness for stars and beetles." Equal parts star and beetle, I'd be willing to bet fireflies would be the beetle people would miss most if they disappeared.
Unfortunately, it does seem that fireflies have declined throughout much of their range. Retired professor Jim Lloyd has studied fireflies since 1962, has personally seen every North American species and has corresponded with hundreds of people about their concern over diminishing firefly numbers. "Bottom line, yes, I think we are quickly losing and have lost many populations of fireflies. Though some species are exceedingly common and will endure and be seen, some are very rare. It is the latter that will go first, if [they're] not gone already," he says.
Though fireflies are rarely spotted in central Houston, I have seen them in the northeast part of town, where the city yields to forest and stream. Scientists speculate that North American firefly declines could be caused by loss of habitat, increases in the amount of light in the environment and pesticides.
The Japanese word for firefly, hotaru, implies harmony between humankind and all other creatures on the planet. Yet because many rivers and streams had been converted into concrete-lined channels and polluted by chemicals, development took away much of the habitat needed by the fireflies' glow-worm larvae. Japan spent around $180,000 on a community-based environmental initiative that restored the Kokumano River and brought back fireflies – dubbed the Hotaru Project. Scientists built a firefly breeding facility and reintroduced larvae to the ecosystem in the early 1980s. Similar efforts could restore fireflies to regions where they've disappeared, but so far biologists in the United States have not tackled such a project.
The first time these Holy Trinity fifth graders saw fireflies will surely remain a cherished memory. Nobody got scared or disgusted by them – unlike a giant brown spider on my tent tarp. It amazes me how a simple flying beetle with a glowing posterior can transform kids' attitudes toward insects from "eww," "yuk" and "gross" to "cool," "wow" and "awesome!"