Butterfly spotted in Delhi in 2018 was last seen in 1962: Researchers
A rare butterfly species ‘Common Lineblue’, which was last seen in 1962 in Delhi, has resurfaced in the national capital after a gap of over half a century, and was spotted by researchers from Delhi University in August 2018.
The researchers had more good news in store. Another rare species, the ‘Dark Cerulean’, was spotted at least thrice between October 2018 and February 2019 in two different places in Delhi. This species was last spotted in the late 90s and before that in 1985. Both Common Lineblue and Dark Cerulean are usually found in the Himalayan foothills.
The resurfacing of the two rare species have prompted researchers and lepidopterologists in the city to speculate that the city’s floral diversity could be changing, attracting new butterfly species from adjoining places.
A male Common Lineblue was spotted at Shalimar Bagh Garden in northwest Delhi by assistant professor Rajesh Chaudhury and laboratory technical expert Vineesh Kumar from the biomedical science department at Acharya Narendra Dev College. The findings were reported in Bionotes, an Indian quarterly research newsletter.
“There is only one record of Common Blueline (Prosotas nora), from 1962 of three male butterflies,” Chaudhury said.
According to the recently published paper, the first partial list of butterflies of Delhi was prepared in 1912 and it contained 21 species. A more elaborate list comprising 62 species was prepared in 1942 and later, in 1967, the list contained 77 species of butterflies.
The list was expanded to include 86 species in 2002. A list of 115 species of butterflies seen in Delhi was published in 2017.
“In 2017, at least 69 butterfly species were recorded from across 14 forest patches in Delhi during a count. In 2018, the number went up to 75 across 51 locations in the city,” Sohail Madan, centre manager of Bombay Natural History Society at Asola Bhatti Wildlife Sanctuary, said.
Researchers said there could be many reasons for more butterfly species being sighted.
“Residents and institutions bring in flowering plants for their balconies and gardens, which are exotic and new to Delhi. Some of these could be hosts to butterflies and in turn, attract more from adjoining areas. Secondly, while transporting fruits and vegetables to the market, unknowingly, people also transport eggs, pupa and larva of butterflies. Upon metamorphosis, butterflies emerge and become residents of Delhi in the course of time,” Surya Prakash, a scientist with the School of Life Sciences in Jawaharlal Nehru University, said.