ABOVE: A group of tropical fireflies (Pteroptyx malaccae) illuminate a tree in Thailand.
RADIM SCHREIBER

An hour’s drive southwest of Bangkok, Thailand, tucked into a curve of the Mae Klong River, lies the village of Amphawa. Until recently, tourists flocked here to watch a spectacular evening light show. Thousands of male Pteroptyx malaccae fireflies would gather in the three-story-tall mangrove trees that line the Mae Klong and flash in synchrony. “It looks like a big Christmas tree with lots of tiny lights,” says Anchana Thancharoen, an entomologist at Kasetsart University in Thailand who has studied fireflies for more than two decades.

The district government started promoting firefly tourism in Amphawa back in 2004. Within just a few years, hundreds of motorboats were zooming up and down the river each night. New hotels, restaurants, and roads transformed the “quiet, peaceful province into an urban area,” says Thancharoen. By 2014, due to light pollution and loss of habitat, firefly numbers had fallen by about 80 percent, all but extinguishing the dazzling displays. These days, most tourists visit Amphawa not for fireflies, but to shop at the floating markets for food and souvenirs. 

There’s been a tremendous growth in insect festivals, some of them are amazingly large.

—Glen Hvenegaard, University of Alberta

It’s a pattern that Thancharoen and other firefly researchers worry could be repeated as the popularity of firefly watching grows worldwide. Thancharoen says she hopes Amphawa’s mistakes serve as a lesson for other sites looking to capitalize on local invertebrate fauna—before it’s too late. 

Fireflies—or lightning bugs, depending on where you’re from—are actually beetles in the family Lampyridae. Generated by a chemical reaction in light-producing organs called lanterns, the green or yellow flickers are the insects’ elaborate courtship displays. It’s “the love language of fireflies,” explains Thancharoen. Although the females and larvae of some species produce light, it’s usually the males that put on the flashiest shows.

The practice of watching this spectacle has a long history in some countries such as Japan, says Sara Lewis, an evolutionary ecologist at Tufts University who studies the sex lives of fireflies. But in recent years, “firefly tourism really seems to be taking off, partly driven by the popularity of the images that people are taking” and sharing on social media, she says. The phenomenon is part of a larger trend of insect-related tourism—or entomotourism. “There’s been a tremendous growth in insect festivals, some of them are amazingly large,” says Glen Hvenegaard, an environmental scientist at the University of Alberta. Every year, tens or hundreds of thousands of tourists swarm to monarch butterfly migratory sites in Mexico, glowworm caves in New Zealand and Australia, woolly bear caterpillar festivals in the US, and insectariums across the world.

HANGING ON: The females of many firefly species lack wings, making them especially vulnerable to trampling in areas with lots of human activity.
RADIM SCHREIBER

Through interviews, surveys, and internet searches, Lewis, Thancharoen, and their colleagues recently quantified global tourism for fireflies, specifically. The researchers found that firefly tourist destinations are dotted across 13 countries in North America, Asia, and Europe. At smaller sites such as the Pennsylvania Firefly Festival, just 1,000 or so people come to watch Photinus carolinus displays, while some places in Taiwan and South Korea draw as many as 200,000 tourists each season. In 2013, about 51,000 tourists visited the tiny town of Nanacamilpa in southeastern Mexico to watch the synchronous spectacle of Photinus palaciosi that occurs for just two weeks each year. By 2019, that number had grown to more than 120,000, says study coauthor Tania López Palafox, a graduate student in the department of evolutionary biology at the Instituto de Ecología of the Universidad Nacional Autónoma de México who works on this species.

The researchers’ study is a “timely” effort to understand threats to the beetles and encourage sustainable practices, notes David Merritt, an entomologist at the University of Queensland who was not involved in the work. “It gives managers of tourism and environmental managers something to work from,” he adds.

All in all, the researchers estimate that more than 1 million people traveled to watch fireflies around the world in 2019. “That really knocked our socks off,” says Lewis. “It’s great for the tourists—they get this amazing experience—and it’s great for local communities, which in many cases are getting a substantial economic boost.” But tourism isn’t necessarily great for the beetles, which, like many insects, are facing global declines. “We would love to make it a win-win-win situation, including a win for the fireflies,” she adds.

See Q&A: Global Insect Declines Due to “Death by a Thousand Cuts

To ensure that firefly populations thrive even as tourist numbers grow, it’s crucial to protect fireflies at all stages of the insect lifecycle Lewis, Thancharoen, and their colleagues say. In Amphawa, motor oil polluted the river, and waves generated by the boat traffic washed away the riverbanks, destroying habitat for P. malaccae larvae. The researchers suggest that tours use nonmotorized or electric boats to minimize the impacts on species with water-dwelling larvae. At sites with species that have subterranean larvae, visitors should stick to designated paths or walkways to avoid compacting soil and trampling the insects. 

The other main threat to the bioluminescent beetles at tourist sites is light pollution, which interferes with the fireflies’ courtship displays, spoiling their chances of finding mates, says Thancharoen. This means that artificial lights from buildings, streetlights, and cars should be minimized at firefly sites, and tourists should refrain from using cellphones, flash photography, and flashlights.

“We know enough about . . . the things that fireflies need to survive to be able to protect species against some of the threats associated with tourism,” says Lewis. But, she adds, protecting the insects can be complicated by the social and economic factors unique to each location. In Amphawa, “there were a lot of conflicts between what fireflies needed, what the local community needed, and what the tour operators were doing.” During the peak of Amphawa’s popularity, 200 motorboats zipped tourists up and down the river for hours each night, sometimes until midnight, prompting one fed-up resident to cut down a firefly display tree, says Thancharoen. Although some locals reaped economic benefits from tourists, many of the new businesses were run by people from outside the community.

To minimize these types of conflicts and ensure that local residents benefit from firefly tourism, it’s important to involve communities in designing, planning, and operating tourist sites, says study coauthor Harvey Lemelin, a social scientist at Lakehead University in Canada who says he became interested in insects after attending a dragonfly symposium. “I looked into those big multifaceted eyes . . . and I fell in love with them,” he recalls. He says that “inclusion of local people in terms of their stories, their narratives, their experience, their traditional knowledge is an essential component [of sustainable tourism].” By bringing these perspectives, local tour guides can help make entomotourism not just an entertaining activity, but an experience that teaches visitors to care about insects and their conservation, he says.

In Amphawa, Thancharoen and others have installed educational displays about firefly biology and conservation and run training programs for tour operators, local residents, and children. Now that just a few boat tours shuttle tourists along the Mae Klong each night, firefly populations are slowly rekindling, says Thancharoen. “Fireflies have started to come back.”