Fireflies under threat in Goa: Experts

Shahin Bepari Lambe

Panaji

The glowing fireflies that have traditionally illuminated Goa’s rural landscape during the monsoon season are facing a steep decline. Experts have warned that habitat destruction, human activity, and rising artificial light pollution heavily threaten the insects’ survival.

A recent study by Ayan Paul, a researcher associated with IIT Kharagpur, has revealed that India has recorded widespread drop in firefly sightings, with some areas experiencing up to a 70 per cent decline within a single year.

India is home to roughly 45 to 50 documented firefly species, with the Western Ghats serving as a primary region for their diversity.

According to the study, fireflies require moist, undisturbed environments rich in soil, leaf litter, and vegetation, as they spend the majority of their life cycles as larvae in the soil.

“Fireflies are not only cultural icons but also critical bioindicators whose presence shows healthy ecosystems,” the study has noted.

Naturalist Omkar Dharwadkar recalled that just two decades ago, fireflies were a common monsoon sight, flashing in large numbers around villages, open spaces, and even entering homes. Today, such sightings have become increasingly rare. Fireflies depend entirely on darkness to communicate and locate mates.

During their breeding period from late May to mid-June, they gather in trees for elaborate courtship featuring synchronised, species-specific flashing patterns.

“Darkness is essential for their breeding activity,” Dharwadkar said adding that when there are brighter lights around, their signals become negligible compared to artificial lighting, and they may not be able to find each other.

Beyond their aesthetic appeal, fireflies are vital to the food chain, serving as a food source for various ground and tree-dwelling organisms. They are also believed to contribute to pollination in some areas.

Dharwadkar warned that a reduction in pollinators can disrupt flowering and fruit-bearing plants, triggering ecological imbalances where certain species may decline while others overpopulate.

Parag Rangnekar, former president of the Goa Biodiversity Board, explained that fireflies are actually beetles. Because the females are flightless, they rely strictly on bioluminescence—natural light production—to attract mates.

“Any kind of artificial light interferes with this communication, affecting their breeding process,” Ranjrekar said. “This is one of the reasons why fewer fireflies are seen in urban areas with high light pollution.”

Rangnekar added that firefly larvae act as natural predators that control populations of slugs and snails, their primary prey. “The presence of fireflies is a good indicator of ecosystem health,” he concluded.