Rare Bat Species in Karnataka Preys on 4,100 Insects

A critically endangered bat found in just one cave in Karnataka can consume prey from more than 4,100 insect species, including mosquitoes associated with dengue and malaria and pests that damage crops, an Osmania University study has found, offering new evidence of the role bats play in pest control and ecosystem health.

The study, published in the ‘Journal of Threatened Taxa’, examined four species of leaf-nosed bats living together in a cave at Hanumanahalli in Kolar district. The cave is the world’s only known habitat of the Kolar Roundleaf Bat (Hipposideros hypophyllus), whose population is estimated at fewer than 300.

Researchers used DNA metabarcoding, a technique that identifies organisms through genetic material, to analyse insect remains in bat guano and determine what the animals had eaten. The study found prey belonging to more than 4,100 insect species in the diet of the Kolar Roundleaf Bat, while the other bat species studied had diets covering between 1,200 and 2,400 insect species.

Among the prey identified were mosquitoes associated with the transmission of dengue and malaria, the tomato leaf miner moth, an agricultural pest, and cockroaches that can carry disease-causing microorganisms.

“Bats are often misunderstood, but they are vital for our health and food security,” lead author Dr Bhargavi Srinivasulu said. The findings showed that the bats were consuming major pests and functioning as “natural bio-controllers”, she said.

The four bat species were also found to have different dietary preferences despite sharing the same cave. Researchers said this specialisation allows them to coexist while collectively feeding on a broader range of insects. Their diets also changed seasonally, indicating that the bats adjust their feeding patterns as insect availability changes through the year.

Co-author Dr Aditya Srinivasulu said identifying what the bats eat was important for designing conservation measures and understanding the ecosystem services they provide.

Prof. Chelmala Srinivasulu, head of Osmania University’s Wildlife Biology and Taxonomy Lab, said the research was the first use of DNA metabarcoding to study bat diets in India. The non-invasive method could also provide a basis for studying biodiversity elsewhere in the country.

The findings assume particular importance for the Kolar Roundleaf Bat because its entire known population depends on a single cave. Researchers said conserving the habitat could therefore protect not only a critically endangered species but also the pest-control services the bats provide to agriculture and surrounding communities.