A Dragonfly Lost for 110 Years — Found Again in Arunachal Pradesh

General Studies Paper 3 — Environment and Biodiversity
Source: Journal of Threatened Taxa, 2026

1. What happened

A rare dragonfly — the long-tailed duskhawker — was rediscovered in Namdapha National Park and Tiger Reserve, Changlang district, Arunachal Pradesh after 110 years. It was last recorded in India during the Abor Expedition of 1914. Four citizen scientists — including a policeman, professors, and wildlife enthusiasts — made the discovery, published in the Journal of Threatened Taxa.

The insect with two compound eyes was last described from the erstwhile Abor Hills area of the State in 1914.

2. Species Profile — Key Facts at a Glance

• Scientific name: Gynacantha khasiaca
• Order / Family: Order Odonata / Family Aeshnidae
• IUCN status: Data Deficient (DD) — too little known about its population
• Behaviour: Crepuscular — active only at dawn, dusk, or on overcast days
• Habitat: Shaded forests, freshwater sources, tropical and subtropical rainforests
• Other countries: Bangladesh, Myanmar, Nepal. In India — Assam, Meghalaya, West Bengal, Uttarakhand

Odonata as bio-indicators: Dragonflies and damselflies (Order Odonata) are extremely sensitive to water pollution. Their presence in a water body is a direct sign of a healthy, clean freshwater ecosystem — making their rediscovery ecologically significant.

3. Namdapha — Why It Matters

• Location: Changlang district, Arunachal Pradesh — near the international border with Myanmar
• Largest protected area in the Eastern Himalaya biodiversity hotspot
• Altitudinal range: From tropical rainforests at the base to alpine meadows above 4,500 metres
• Only park in the world with all four big cat species — Snow Leopard, Clouded Leopard, Common Leopard, and Tiger

4. Value Box — Key Terms

Data Deficient (DD) — IUCN Category

Assigned when there is not enough information to assess extinction risk. Does not mean the species is safe — it means we simply do not know enough. Cannot get targeted legal protection without data.

Citizen Science

Involving non-professional volunteers — local communities, enthusiasts, students — in systematic scientific data collection. Highly effective for biodiversity documentation where official staff is limited.

Eastern Himalayas Biodiversity Hotspot

One of the world’s 36 biodiversity hotspots. Covers parts of northeast India, Bhutan, Nepal, and southern China. Exceptionally rich in endemic species — many still undocumented by science.

Prelims Practice Question

Consider the following statements regarding the long-tailed duskhawker and Namdapha National Park:

1. The long-tailed duskhawker belongs to the Order Odonata and is currently classified as Data Deficient by the International Union for Conservation of Nature.
2. Namdapha National Park is the only protected area in the world known to harbour all four big cat species — Snow Leopard, Clouded Leopard, Common Leopard, and Tiger.
3. Species of the Order Odonata are considered bio-indicators of healthy freshwater ecosystems because they are highly sensitive to water pollution.

Which of the statements given above are correct?

• (a) 1 and 2 only
• (b) 2 and 3 only
• (c) 1 and 3 only
• (d) 1, 2 and 3

Correct Answer: (d) 1, 2 and 3