A recent study has revealed an “alarming gap” in biodiversity across the Western Ghats, with researchers able to document only about 65% of the dragonfly and damselfly species historically recorded in the region, pointing to a potential shortfall of nearly 35% of these ecologically critical insects.

The survey recorded 143 odonata species—76 dragonflies and 67 damselflies—of which 40 were endemic to the Western Ghats. The study was carried out across 144 sites spanning five States between February 2021 and March 2023. 

Three species—Elattoneura Souteri, Protosticta Sanguinostigma and Cyclogomphus Ypsilon—are currently classified as vulnerable, while most of the observed species fall under the “data deficient” and “not evaluated” categories on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, indicating significant gaps in scientific understanding.

The study was conducted in 105 sites of Maharashtra, recording 100 species, including 12 endemic ones. In Kerala, 14 sites showed a high concentration of endemic diversity with 33 endemic species. Karnataka revealed 64 species with 6 endemics across 17 sites, Goa documented 35 species, including 4 endemics, across 3 sites, and 5 sites in Gujarat recorded 18 species with no endemic ones.

Emphasising the urgency of expanding research, Dr. Pankaj Koparde, Assistant Professor, MIT-World Peace University Pune, said, “This study is a result of one of the most extensive Odonata surveys across the Ghats. Our surveys could recover only 65% of the known Odonata fauna of the Ghats, indicating plausible loss of species and habitats.” 

The Western Ghats is a 1,600-km mountain chain along India’s west coast and a globally recognised biodiversity hotspot. The survey team, headed by Professor Koparde, suggested that the Odonata species are highly sensitive to environmental changes because they depend on freshwater ecosystems for reproduction, widely regarded as “indicator taxa,” meaning their presence, or absence, directly reflects the ecological health of water bodies. So, the missing species may be early indicators of deeper ecological stress.

The study claimed there are multiple threats across the Western Ghats, including linear infrastructure development, hydropower projects, severe pollution, large-scale land-use changes, unregulated tourism, recurring forest fires, and added that the growing impact of climate change is further fragmenting and degrading these ecosystems.

Findings

According to the IUCN Red List, of the 143 recorded species, 100 species are classified as ‘Least Concern,’ 22 species as “data deficient”, and 16 as “not evaluated”. Two species—Phylloneura westermanni and Heliogomphus promela—fall in the “near threatened category”, while two others—Protosticta san guinostigma and Cyclogomphusypsilon—are listed under “vulnerable” category.

The presence of 22 species listed under the “data deficient” category suggests the need for extensive surveys across the Western Ghats to uncover the status and distribution of many lesser known odonata species. 

The two-year study also documented new spatial records of several odonata species as well as the discovery of several new taxa from the Western Ghats.

Several surveys carried out in the northern Western Ghats of Maharashtra aid in gaining new spatial odonate records from the region, namely Macromidia donaldi donaldi (genera incertae sedis) from Pune, Merogomphus longistigma (Gomphidae), and Idionyx saffronata from Satara and Gynacantha khasiaca from Raigad. 

The study also uncovers the richness of odonata species from several localities across five States of the Western Ghats, many of which were previously undersampled or unexplored. The findings demonstrate that the diversity and degree of endemism of odonata species are greater in the southern Western Ghats compared to the northern part of the region. This can largely be attributed to the availability of suitable microhabitats and perennial streams in the southern Western Ghats (particularly south of Coorg and in Kerala).

The findings of the study indicate the need for more intensive surveys in unexplored areas of the Western Ghats to fill existing knowledge gaps and to achieve a better understanding of the status and distribution of odonata species.