Dragonfly count nearly doubles in Delhi

A survey of dragonflies and damselflies across seven biodiversity parks in Delhi has revealed that while the number has significantly increased compared to last year, the diversity in species has reduced at some places. Scientists said a total of 8,630 flies have been recorded this year, higher than previous year’s 4,540.
The three-day dragonfly and damselfly survey was conducted across seven DDA biodiversity parks of Yamuna, Aravalli, Neela Hauz, Tilpath Valley, Kamla Nehru Ridge, Tughlaqabad and Kalindi from September 18 to 20, with the help of students from colleges and universities across Delhi NCR.
Officials said that the prolonged monsoon over the last three months could be the reason for the rise in number of these insects, which form a part of the “odonata” family. Odonatas are characterised by large round heads, compound eyes, two pairs of long, transparent wings and elongated abdomens.
“This rise in numbers is closely correlated with the extended monsoon in the region this year, which has led to more favorable conditions for breeding and habitat availability. Dragonflies and damselflies thrive in wetland environments, and the prolonged rainfall has contributed to the formation of ephemeral wetlands and enhanced the availability of aquatic habitats,” Faiyaz Khudsar, scientist-in-charge, DDA biodiversity parks programme, said.
He added that Wandering Glider and Ditch Jewel were most sighted species of dragonflies across all the biodiversity parks indicating their wide range of tolerance and suitable habitats in urban landscapes of Delhi.
Kamla Nehru Ridge recorded the largest number of flies — 3,150 among 25 species, while Kalindi biodiversity park recorded 2,840 individuals among 14 species. Among 21 species, 1,008 dragonflies and damselflies were seen in Yamuna biodiversity park. Data shared by the biodiversity parks programme also showed a total of 4,540 flies were recorded last year while the count was higher in 2022, at 5,219.
Meanwhile, certain areas recorded a fall in the number of species. In Tughlaqabad, the number of species was recorded at 12 this year, a drop from last year’s 14 and at Neela Hauz, the count reduced from 13 to 5. However, officials said that the individuals from every species showed a higher count this year.
Khudsar said that amid the rising cases of dengue in Delhi, the increase in number of dragonflies points at a healthy environment.
“Dragonflies and damselflies serve as essential indicators of environmental health due to their dependence on clean and oxygenated water. Their sensitivity to water pollution makes them valuable bioindicators, reflecting the overall quality of aquatic ecosystems. Moreover, they play a dual role in the food web, acting as both predators of insects and prey for birds and fish. A single dragonfly can consume between 30 and 100 mosquitoes each day, making them a crucial natural pest control,” Khudsar explained.
The dragonfly count was first done in 2018 across three biodiversity parks.