Hugged by clouds and nestling in the Western Ghats, the pristine hills of the Meghamalai in Tamil Nadu have thrown up a new species of ‘silverline’ butterflies.
Lepidopterists from Tamil Nadu and Kerala stumbled upon the new species, Cigaritis meghamalaiensis, from the biodiversity-rich hills of the Periyar landscape during an expedition conducted in 2021. It has become the first butterfly species to be described from the Western Ghats in 33 years.
The researchers from the Thiruvananthapuram-based Travancore Nature History Society (TNHS) and Vanam Trust, Theni, had first come across the distinct species belonging to the Cigaritis genus in the high elevations of Periyar in Idukki in 2018. Further explorations have revealed the species to be confined to the Meghamalais and the adjoining Periyar Tiger Reserve. The findings have been described in the peer-reviewed journal Entomon.
“The discal and post-discal bands on the forewing underside of the adult butterfly are conjoined and lie parallel from their origin at the costa. The unique feature distinguishes the new species from all other Cigaritis occurring in Peninsular India and Sri Lanka,” TNHS research associate Kalesh Sadasivan, who led the discovery, said.
Co-author Ramaswamy Naicker of Vanam Trust points out there are seven species of Cigaritis in the Western Ghats, viz., C. vulcanus, C. schistacea, C. ictis, C. elima elima, C. lohita lazularia, C. lilacinus, and C. abnormis. Of these, all except C. lilacinus have been reported from the southern Western Ghats.
The other members of the study include Sujitha P.C., Baiju Kochunarayanan, Jebine Jose, Manoj Kripakaran, Rajkumar Chidambaran Palaniappan and Vinayan Padmanabhan Nair.
According to the researchers, a hitherto-unreported taxon was last described from the Western Ghats in 1990 – Eurema (Terias) nilgiriensis (Yata, 1990), or the Sahyadri Grass Yellow (Nilgiri grass yellow). Ever since, three subspecies, viz., Eurema (Terias) andersoni shimai Yata & Gaonkar, 1999, Nacaduba sinhala ramaswamii Sadasivan 2021, and Caltoris bromus sadasiva Sadasivan & Kunte, 2023, have been discovered from the mountain range.
With the discovery, the total number of butterflies in the Western Ghats has risen to 337 species including 40 Western Ghat-endemics.
