COIMBATORE: Anamalai Tiger Reserve (ATR) provides a conducive habitat for nearly eight firefly species, according to a study – which is first of its kind in the state – carried out by Tamil Nadu forest department’s Advanced Institute for Wildlife Conservation (Research, Training and Education) about the insect’s diversity, distribution, habitat and their ecology in ATR.
The study was carried out for a period of 10 months between May 2024 and March 2025 under the annual plan operations 2023-24 in 10 different locations within the ATR. This was to understand the assemblage of firefly species, seasonal changes in their population, environmental conditions in the lightning bug’s habitats and their genetic diversity.
According to S Senbagapriya, Deputy Director of AIWC, “Eight firefly species, namely Abscondita perplexa, Ab. terminalis, Asymmetricata humeralis, Curtos sp. 1, Curtos sp. 2, Lamprigera sp., Pyrocoelia sp. and one unidentified sp., were collected during the study. The phototactic movement behaviour of A. perplexa was studied and the results clearly showed that fireflies preferred darkness and avoided six colours, namely blue, green, yellow, orange, pink and red. White light was neither preferred nor avoided by the fireflies.”
She said, “Studies on fireflies’ habitats, preferred environmental conditions, and interactions with other organisms help us understand the ecosystem health and develop strategies to conserve firefly habitats and maintain ecological balance.”
The highest number of firefly specimens (93 individuals) was collected at Saralapathi (in agroecosystems) near Pollachi in Coimbatore district, where Ab. terminalis was the only species.
According to the study, a total of eight species were documented from ATR, representing a significant increase in species richness compared to earlier studies, where only three species were recorded from the Ulandhy range by a team led by researcher Sriram in 2023.
In the questionnaire survey conducted among the 171 participants, only 166 individuals reported having seen fireflies in the ATR region. This survey among the local people clearly showed that 97% of people have knowledge about fireflies, and the decline in firefly population was mainly due to pesticide use and water pollution.
“Fireflies are incredibly sensitive to changes in their habitats, especially to pollution, habitat disruption, and light contamination. So, preserving forests, wetlands and meadows is essential for their conservation.” the study found.
The lowdown on lightning bug
Firefly is one of the most celebrated insects worldwide
Fireflies possess the unique ability to produce bioluminescence due to the presence of specialised light-producing organs called lanterns
Fireflies serve as important bioindicators of ecosystem health due to their sensitivity to environmental changes
Their presence reflects the availability of fresh air, unpolluted water, healthy soil (vegetation) and balanced ecosystems
Decline in firefly population often results from habitat degradation caused by pollution, excessive pesticide use, exposure to bright high-voltage LED lights, urbanisation, and changing climate patterns