An insect that enjoys a near-360° vision with thousands of lenses, and can stay still in the air, has resurfaced in Arunachal Pradesh’s Changlang district, about 600 km east of where it was first recorded 110 years ago.

A team of four citizen scientists recorded Gynacantha khasiaca, a rare dragonfly commonly known as the long-tailed duskhawker, from the Namdapha National Park and Tiger Reserve. This insect with two compound eyes, each with thousands of tiny lenses and photoreceptor clusters, was last described from the erstwhile Abor Hills in 1914.

Mahesh R. from Kerala’s Ernakulum, Rajesh Gopinath from Karnataka’s BMS Institute of Technology and Management, Gaurav Joshi from Uttarakhand’s Haldwani, and Roshan Upadhaya, a policeman from Arunachal Pradesh’s Basar, are the authors of a study on the “rediscovery” published in the Journal of Threatened Taxa.

According to the authors, the long-tailed duskhawker was sighted at Deban in October 2024 and confirmed through photographs taken in the presence of the forest staff. They said that the finding has underscored the need for continued monitoring and habitat protection in India’s easternmost State.

Dragonflies and damselflies, belonging to the order Odonata, are crucial components of freshwater ecosystems, as predators and prey in the aquatic food web. The global diversity of Odonata comprises 6,442 species across 693 genera.

India is home to 504 species and 27 subspecies across 152 genera and 18 families. The total number of species in Arunachal Pradesh is 110. The genus Gynacantha includes large dragonflies with pale brown and green colouration and crepuscular behaviour.

This genus comprises 92 species globally, with approximately 30 species recorded in Southeast Asia, and 10 species documented in India.

The authors recorded 17 Odonata species during their study period. These included the Trithemis aurora, Neurothemis fulvia, Orthetrum glaucum, Aristocypha spuria, and Neurobasis chinensis.

“As a highlight among these observations, a single male specimen of Gynacantha khasiaca was observed on October 16, 2024, around 8 a.m. on a cloudy day along the Miao-Vijoynagar Road (altitude of 600 m) within the Namdapha National Park and Tiger Reserve. The male was initially observed rapidly patrolling the road edge and hovering while defending its territory,” their paper said.

Outside India, the long-tailed duskhawker has been recorded in Bangladesh, Myanmar, and Nepal. In India, beyond Arunachal Pradesh, it has been documented in Assam, Maharashtra, Meghalaya, Uttarakhand, and West Bengal.

The location nearest to Deban, where this dragonfly was recorded in 2017, is Deopahar, about 400 km southwest in Assam’s Golaghat district.