For tens of millions of individuals across the globe, fireflies have been a giant a part of the magic of spring and early summer nights. They definitely were in our family. When my children were young, our field in central Massachusetts blazed with fireflies.
Before our firefly expeditions within the Nineteen Eighties I’d recite “All About Fireflies All About,” wherein David McCord celebrates “little lanterns sailing by, like stars across a mimic sky.” We’d catch fireflies in butterfly nets, and Scott and Beth would keep them in glass jars by or of their beds. The next morning I made sure they released them where we caught them. In 2023 I saw three fireflies in our field.
Children should pursue fireflies early and sometimes. Never will they forget coursing through high grass, sweeping little lanterns from that mimic sky.
Fireflies (beetles, not flies) exist on every continent save Antarctica. There could also be as many as 2,400 species, and recent ones are being discovered. Because the adult season winds down within the North American autumn, it starts or is ongoing elsewhere. The larval season is continuous all over the place.
Yet some firefly populations are in trouble. Evidence thus far is generally anecdotal. Still, in North America alone, the Firefly Specialist Group of the International Union for Conservation of Nature (IUCN) has identified 18 species as “liable to extinction.”
Latest LED streetlights, touted as environmentally friendly, seem like disrupting reproduction of Britain’s glow-worms.
The gravest threat is habitat destruction. This from Ben Pfeiffer, founding father of the tutorial group Firefly Conservation & Research: “I live in considered one of the fastest-growing areas within the nation — between Austin and San Antonio, Texas. Firefly habitat is being converted to dense development at a ridiculous rate. Every year hundreds of acres disappear.”
Water pollution has been liable for much decline, especially in Asia where larvae of many firefly species are aquatic. And within the southeast a part of the continent, razing mangroves to make way for shrimp farms and palm-oil plantations is killing off Pteroptyx firefly species in addition to the snails the larvae prey on.
A Thai boatman who grew up with fireflies along the tidal rivers of Bangkok estimates firefly populations there have dropped 70 percent. “I feel like my lifestyle is being destroyed,” he told Sara Lewis, a retired Tufts University biology professor who now co-chairs the IUCN Firefly Specialist Group and is the creator of a book about fireflies, Silent Sparks.
Forests in Brazil and Mexico, which have a few of the richest firefly diversity, are losing populations to clearcutting and fragmentation.
An eastern firefly, also referred to as a giant dipper, probably the most common firefly species in North America.
E.R. Degginger / Alamy Stock Photo
Pesticides and lawn chemicals are major limiting aspects. Mosquito spraying kills nontarget insects including fireflies. And homeowners douse their lawns with all manner of elixirs deadly to firefly larvae and their prey, each of which live in soil and leaf litter.
Most fireflies use species-specific flash codes to seek out mates. But light pollution blinds the flying males in order that they can’t find the females. And the sedentary females (in some species they’re wingless) can’t move to darker areas.
Latest LED streetlights, touted as environmentally friendly, seem like disrupting reproduction of Britain’s glow-worms. The male’s eyes are tuned to the feminine’s green light, but under the LED blue light males struggle to seek out females.
Fireflies produce cold light by oxidizing luciferin with the enzyme luciferase, useful in food-safety trials and biomedical research. Starting in 1947 McElroy’s Lab in Baltimore sponsored firefly harvesting, paying children 25 cents per hundred, then snipping off the fireflies’ lanterns and hawking the contents. Soon McElroy’s was killing one million fireflies a yr for granted for rare species. Other corporations joined in. St. Louis-based Sigma Chemical Company, for example, bountied fireflies of any and all species at a penny a chunk as a part of its “Firefly Scientists Club open to all Boy Scout groups, church groups, 4-H clubs, and individuals.” By the early Nineties, Sigma had killed “greater than 100 million fireflies,” reports Lewis.
Firefly ecotourism has turn out to be an enormous business. Taiwan’s and Mexico’s firefly shows each draw about 100,000 visitors a yr.
But there’s excellent news, too. Since synthetic luciferase became available in 1985 the business slaughter has sharply diminished, and a few populations are recovering. Firefly ecotourism has turn out to be an enormous business, inspiring restoration. Taiwan’s and Mexico’s firefly shows each draw about 100,000 visitors a yr, Malaysia’s 80,000.
The three groups of fireflies include: lightning bugs, flightless glow-worms, and dark fireflies whose eggs and larvae glow but whose adults lack lanterns and fly by day, locating mates by scent.
Larvae can live for 2 years. But most adults don’t live way more than two weeks. They mate abdomen to abdomen, coupled all night. Together with sperm, the male gives the feminine a “nuptial gift” — a protein package for egg production.
Within the high country of Tennessee and North Carolina, a few of the most spectacular fireflies light up in synchrony, with males flashing six times in rapid succession, then going dark for six seconds. Ground-based females respond dimly or with a double flash.
Fireflies in Nanacamilpa, Mexico.
Rebecca Blackwell / AP Photo
In 1991 Lynn Faust of Knoxville, Tennessee read an article in Science News proclaiming that there have been no synchronous fireflies within the Western Hemisphere. But she’d been watching synchronous shows round her family’s cabin in Great Smoky Mountains National Park because the Nineteen Sixties. She contacted the scientists quoted within the article and set them straight.
Today Faust is a member of the IUCN Firefly Specialist Group. The synchronous “light show” she introduced to the world now brings hundreds of tourists to the park each June. About 30,000 applicants compete for 1,800 parking spots.
Round her farm in east Tennessee Faust is “surrounded by lightning bugs” — no less than 26 species with such evocative names as Chinese lanterns that float near the bottom at twilight, heebie-jeebies that sparkle constantly from trees, blue ghosts (that emit blue, minute-long flashes and whose wingless females guard their eggs), snappy syncs (that light up synchronously), shadow ghosts, 4 flashers (that flash 4 times), sidewinders (that flash sideways), woodland lucys, little grays, winter fireflies, pink winkers, bush babies, and spring treetop flashers.
You’ll be able to converse with most firefly species for those who study their flash codes and imitate them with a penlight.
Spring treetop flashers appear early within the yr. They will freeze solid, fall off a tree, then get better. Males hatch first, locate a female pupa, climb on top, and embrace her with their legs. Except to fight off rivals, the male never moves until the feminine emerges and so they mate. Unlike the soil-dwelling larvae of other fireflies, these larvae climb trees, in order that they’re the one ones you’re prone to see pupate. They glue their tails to the bark and hang the other way up, at all times on the tree’s south side.
Firefly larvae are voracious predators of snails, slugs, worms, and soft-bodied insects. But the overall considering is that adults don’t eat. It’s not true. Kids who catch fireflies can keep them alive longer in the event that they drop a slice of apple within the jar.
In all life stages fireflies contain toxins that make them repugnant to predators. Larvae and eggs glow constantly, as a warning. And while nobody has determined how fireflies acquire toxins, Faust has an idea. Sooner or later she was riding her horse through a milkweed field, and even from that top perch she saw so many fireflies on milkweed that she dismounted. They were clearly nectaring on the flowers, which like all parts of the plant, contain the cardiac glycosides that protect monarch butterflies from predators.
The common European glow-worm.
blickwinkel / Alamy Stock Photo
One group of fireflies, called femme fatales, can’t acquire toxins except by purloining them. The massive females imitate the feminine flash responses of other species. When a male involves mate, the femme fatale seizes him along with her long legs and devours him. She can even pick off males in flight and steal fireflies from spider webs. Lewis, the IUCN Firefly Specialist Group’s co-chair, tells of how her nephew Nate, then five, was horrified one morning to see a pile of body parts in his firefly jar. “My fireflies got murdered,” he lamented. There was just one left, a bloated femme fatale.
On a family firefly expedition to our neighbor’s farm circa 1985 I flashed a penlight about once every six seconds. Every time a firefly on the bottom 50 yards away responded with a single flash. I had no idea what that meant. I do now. I’d stumbled onto the male flash code of the massive dipper (named for its dipping flash pattern), and a female was answering me.
You’ll be able to converse with most firefly species for those who study their flash codes and imitate them with a penlight. But brilliant light confuses fireflies, making them stop normal behavior. They’re tolerant of blue light. So if you could have to make use of a flashlight to seek out your way, cover it with blue cellophane (available at art supply stores).
Japanese school children now raise fireflies and release them in proper habitat, and there are firefly festivals everywhere in the country.
Alarm about firefly decline is inspiring recovery work. For hundreds of years, fireflies have been central to Japanese poetry, art, and the Shinto belief that sacred spirits grace the landscape. But industrialization, agricultural runoff, pesticide contamination, and harvesting nearly wiped them out. Firefly hunters were selling their catch, sometimes 3,000 an evening, to wholesale shops. From there the fireflies were bagged and delivered by bicycle courier to habitat-bereft cities where they were released for the general public to enjoy and where they promptly died. That practice has been banned.
Japanese school children now raise fireflies and release them in proper habitat, and there are firefly festivals everywhere in the country. Today Japanese fireflies are an emblem of environmental enlightenment and national pride. “While [they] have never been restored to their former glory days,” writes Lewis, “a predictably sad saga was transformed right into a conservation success story by a powerful combination of national, local and personal efforts.”
In america, recovery is just starting. “We’ve been spending numerous effort getting out in the sphere and hunting down old museum records to seek out out what populations are still around,” says Anna Walker of the Latest Mexico BioPark Society, who works with Lewis and Faust on IUCN’s Firefly Specialist Group. “We’re attempting to learn what species have to be petitioned for Endangered Species Act protection.”
Blue ghost fireflies within the Blue Ridge Mountains of North Carolina, captured in a long-exposure photograph.
Radim Schreiber
Petitions to the U.S. Fish and Wildlife Service were recently filed for the Bethany Beach firefly in Maryland and Delaware, the loopy five of Tennessee, Georgia, and South Carolina, the Florida intertidal firefly, and the Southwest spring firefly.
Firefly recovery depends heavily on citizen science. The Xerces Society has a program called Firefly Atlas where people can take online training and report trends in firefly populations. And the Firefly Conservation & Research has a habitat certification program that teaches grow firefly populations on private land.
Certainly one of the few sanctuaries in North America dedicated specifically to fireflies is in Connecticut — the Marvin, Massarella, & Friends Firefly Sanctuary managed by Latest Canaan Land Trust. But firefly sanctuaries occur by accident when people create, protect, or restore habitat. Butterfly gardens are also firefly gardens. Actually, just about all gardens produce fireflies since the wealthy soil attracts the prey of firefly larvae.
“So long as you possibly can protect or restore their habitats, we’ve got a very good probability of reversing firefly declines.”
You’ll be able to create a sanctuary by: eliminating outdoor lights or no less than putting them on timers; reducing or eliminating pesticides and lawn chemicals; switching to natural fertilizers; planting native forbs, grasses, shrubs, and trees; keeping property moist by creating pools and water gardens; and, the simplest and hottest of all, resisting requests to mow grass and rake leaves.
“When there’s a will to guard species, we may be quite successful, especially with insects because they reproduce in a short time,” remarks Anna Walker. “So long as you possibly can protect or restore their habitats, we’ve got a very good probability of reversing firefly declines.”
Our field in Massachusetts gets blighted by town mosquito spraying. But through the abysmal 2023 firefly showing, I had an epiphany. My family is part-owner of a 280-acre island on a Latest Hampshire lake. There are dozens of vernal pools, a stream, a pond, no outdoor lighting, no mowing, no raking, no use of pesticides or lawn chemicals. We’ve at all times had fireflies, but non-abundant forest species.
Three years ago we did extensive selection logging, planting native grasses in all of the cutover spots. On July 12 I drove across the bridge at twilight, and the plush, recent grasslands were blazing with fireflies — hundreds of them. I felt like I’d been transported back to the Nineteen Eighties. We’d created an accidental firefly sanctuary.
