Night of the firefly
Many of us have fond childhood memories of the जुनकिरी (firefly), chasing the fascinating lightning bugs through fields and forests. Across the world and in Nepal, poets and singers have waxed eloquent about the blinking light of the nocturnal insects.
But for a creature so admired, there has not been much of an effort to study and protect them. As elsewhere in the world, firefly numbers have declined sharply, even prompting the International Union for the Conservation of Nature (IUCN) to set up a Firefly Specialist Group in 2018.
“We grew up playing with fireflies, chasing them around Tundikhel, but those days are long gone,” laments Tirtha Bahadur Shrestha, a noted Nepali naturalist. “Fireflies need a pristine environment, and their very presence signifies undisturbed nature.”
Fireflies belong to a family of beetles called Lampyridae and evolved alongside dinosaurs 100 million years ago. But habitat destruction, rampant pesticide use, light pollution and climate change now threaten to put the lights out on all 2,200 species of fireflies so far identified.
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The decline of fireflies indicates a degradation of the ecosystem, especially of wetlands. Yet, there has been no systematic study of the status, scope and habitat of these glow worms in Nepal.
“The number and diversity of firefly species are unknown in Nepal and researchers have not given priority to these insects,” says Hum Gurung of Singapore-based Birdlife International Asia, who is promoting firefly tourism in Malaysia, and developing a participatory citizen scientist group to study fireflies in Nepal.
Gurung says firefly conservation must begin with first researching them and planning a sustainable eco-tourism model based on firefly viewing, just like the cherry blossom season in Japan or fall colours in New England.
“Their commercial value will add to the efforts to protect them,” he adds.
But in Nepal, these lightning bugs that were once ubiquitous in gardens, jungles, riverbanks, and even streets and playgrounds in the towns have all but disappeared. Where did they all go?
In Pokhara, butterfly researcher Surendra Pariyar says: “I have nostalgic memories of fireflies from my childhood, but as the city’s concrete jungle spreads I hardly see even one firefly these days.”
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Elsewhere in Japan, Southeast Asia and South America, the charismatic beetles with their bioluminescent courtship displays have turned into a major attraction for nature and wildlife tourists.
Extra income from the firefly boat tours was crucial in curbing overfishing in Malaysia’s Kuala Selangor. Fireflies can promote unique, insect-based night tourism with indigenous communities in Bardia and Chitwan in Nepal.
Says butterfly expert Bhaiya Khanal, previously with the Natural History Museum: “Firefly tourism opens up a lot of opportunities including the possibility of finding more species. This, in turn, will promote their conservation.”
Artificial light however is the biggest threat to fireflies as it reduces the beetle’s breeding success. Bright lights from buildings, vehicles, flashlights, and even cell phones can disrupt firefly mating.
Nurturing and protecting the habitat is equally important, especially as the bugs spend most of their life cycle in a larval stage and require several months or even up to three years, to develop into adults.
“We need to understand their lifecycle and its role in the ecosystem, what it feeds on and what preys upon them and our conservation and ecotourism efforts should take all of these into account,” adds Tirtha Bahadur Shrestha.
Fireflies can be a ‘gateway bug’ to get tourists and locals interested in conserving many other insects, often ignored in favour of tigers, rhinos and wild elephants. Nepal is a model for wildlife conservation but its efforts in protecting smaller organisms are nearly non-existent.
But first, proper conservation mechanisms must be put in place so that spreading firefly tourism does not end up destroying the very insect it is trying to save.
A new study published in the journal Conservation Science and Practice provides the first comprehensive review of the geographic scope, magnitude, focal species, and other attributes of the major firefly tourism sites worldwide.
The rapid proliferation of firefly tourism could mean new threats such as inadvertent trampling of female adults and degradation of larval habitats during tours.
“Ultimately we have to change our destructive development methods and work on urban planning that takes into account the health of an ecosystem,” adds Hum Gurung, also co-author of the paper.
Bhaiya Khanal agrees that conservation and development should go hand-in-hand. He says, “New infrastructure projects must not ignore these creatures, we must proactively protect them before they are forever gone.”
What makes them glow?
Fireflies have a romantic morse code for every occasion, whether it is to find a mate, or to scare off predators. It could be a steady glow or a flashing light, differing in duration, timing, colour, and repetition.
All 2,200 identified species have their own blinking codes, glowing to varying degrees during the larva stage but most lose their light-emitting capacity by adulthood. Fireflies are also active during the day when they use chemical signals or pheromones to attract partners.
Fireflies also emit a lightning signal when threatened by predators, or to protect territory. The light comes from a chemical reaction called bioluminescence, and the glow is not hot, but cold to touch.
The lower abdomen of a firefly consists of calcium, magnesium, and a naturally occurring chemical called luciferin. But it is a superoxide ion, an extra electron, that is responsible for pale yellow, green, sometimes orange or blue flickers during hot summer nights.
The reaction can be harmful to living tissue, but it does not affect the insect because the reaction is contained and happens quickly. The toxic luciferin molecule could be the key to a breakthroughs in cancer research and therapy.
Fireflies in Nepal
Only three species of fireflies have ever been recorded in Nepal, and even those were when the first British naturalists came to Kathmandu in the 1830s.
Diaphanea marginellus was spotted at 2,000m in Kavre, so was Luciola ovalis. But the most common species found throughout Nepal is Luciola cruciate, pictured above.
Fireflies prefer hot and humid conditions and are therefore found in the plains and the mid-mountains valleys of Nepal between July-August-- in ponds, streams, marshes and rivers. Fireflies usually are not found above 1,200m altitude, so Kathmandu would be at the upper limit of their habitat.