Journal of Threatened Taxa | www.threatenedtaxa.org | 26 May 2026 | 18(5): 28982–28987

 

ISSN 0974-7907 (Online) | ISSN 0974-7893 (Print) 

https://doi.org/10.11609/jott.9839.18.5.28982-28987

#9839 | Received 10 April 2025 | Final received 21 May 2025| Finally accepted 21 May 2026

 

 

First time in 110 years: sighting of Gynacantha khasiaca Maclachlan, 1896 (Odonata: Aeshnidae) in Arunachal Pradesh, India

 

R. Mahesh 1 , Rajesh Gopinath 2 , Gaurav Joshi 3  & Roshan Upadhaya 4         

 

1 Kattiparambu Madam, Thekumbhagam, Tripunithura, Ernakulam, Kerala 682301, India.

2 OIKOS (Eco-Club), BMS Institute of Technology and Management, Bengaluru, Karnataka 560119, India.

3 Parwati Niwas, Jagat Mangla Colony, Haldwani, District Nainital, Uttarakhand 263139, India.

4 Police Department, Basar, Leparada, Arunachal Pradesh 791101, India.

1 maheshgreen96@gmail.com (corresponding author), 2 dr.rajeshgopinathnair@gmail.com, 3 gauravjoshi.0416@gmail.com,

4 roshanupadhaya14@gmail.com

 

 

Editor: Anonymity requested.                 Date of publication: 26 May 2026 (online & print)

 

Citation: Mahesh, R., Rajesh Gopinath, G. Joshi & R. Upadhaya (2026). First time in 110 years: sighting of Gynacantha khasiaca Maclachlan, 1896 (Odonata: Aeshnidae) in Arunachal Pradesh, India. Journal of Threatened Taxa 18(5): 28982–28987. https://doi.org/10.11609/jott.9839.18.5.28982-28987

  

Copyright: © Mahesh et al. 2026. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use, reproduction, and distribution of this article in any medium by providing adequate credit to the author(s) and the source of publication.

 

Funding: This study was self-funded, and a citizen science initiative by the authors. No fund has been received from any external agency for this study.

 

Competing interests: The authors declare no competing interests.

 

Acknowledgments: The authors wish to acknowledge their sincere gratitude to Office of Conservator of Forests & Field Director, Namdapha Tiger Reserve, Miao, Arunachal Pradesh for providing the necessary logistical support. The authors are also thankful to Shri Autum Rumdo, Department of Forest, Namdapha Tiger Reserve, Arunachal Pradesh for his valuable support rendered during the field work. The authors are also indebted to Ms Nisha Gopinath, WEB (Warriors of Environment and Biodiversity-Environment NPO, Bengaluru 90) for the support rendered in the Image Processing. The authors wish to acknowledge the support Dr. Taslima Sheikh (Citizen Science Expert, Inspire Foundation Trust, Lucknow) for valuable insight and pre-review of Manuscript. Gratitude is also owed to Ms Dilna Chandran (Maharaja’s College - Ernakulam, India), Ms Kavya P.V (Central University of Kerala - Kasaragod, India) and Ms Ashley Shaji (Scientist Ecology Specialist, Scotland) for providing pertinent References needed for the study.

 

 

 

Abstract: This communication reports the first confirmed sighting of Gynacantha khasiaca Maclachlan, 1896 after 110 years at Namdapha National Park and Tiger Reserve for the state of Arunachal Pradesh, India. Also commonly called as Long-tailed Duskhawker, the identification was based on photographic evidence documented in the presence of forest personnel at Deban in the Tiger Reserve during October 2024, and adds to the region’s biodiversity inventory. This finding emphasizes upon the importance of continuous monitoring and habitat preservation of in situ biodiversity conservation.

 

Keywords: Biodiversity, Duskhawker, Deban, eastern Himalaya, ecosystem, entomofauna, insect, Namdapha National Park, rediscovery.

 

 

 

Dragonflies and damselflies (Odonata) are crucial components of freshwater ecosystems, playing significant roles as predators and prey in aquatic food webs (Corbet 1999; Córdoba-Aguilar 2008; Gopinath 2022). The global diversity of Odonata comprises 6,442 species across 693 genera (Paulson et al. 2026), with India being a habitat for 504 species and 27 subspecies from 152 genera and 18 families. The total species count for Arunachal Pradesh is 110 (Mitra 2002). The genus Gynacantha Rambur, 1842, includes large-sized dragonflies with pale brown and green colouration and crepuscular behaviour (Fraser 1936). This genus comprises 92 species globally, with approximately 30 species recorded in southeastern Asia and 10 species documented in India (Khan 2015a; Kalkman et al. 2020).

 

Study area

Namdapha National Park and Tiger Reserve (Figure 1), located in the Changlang District of Arunachal Pradesh, covers approximately 1,985 km², making it one of the largest protected areas in the eastern Himalaya (Arunachal Online 2024). Situated at the confluence of the Patkai Ranges and Dapha Bum Ridge of the Mishmi Hills, it spans latitude 27.383°–27.650° N and longitude of 96.250°–96.966° E. While the dense forest does receive significant rainfall (average annual rainfall 2,500–3,500 mm), the hilly areas also have a profound mountain climate influence upon it (Arunachal Online 2024). It also features a dynamic riverine ecosystem alongside the Noa-Dihing and Namdapha rivers (Sathyakumar et al. 2011).

With an elevation range of 200 m to over 4,571 m, Namdapha National Park and Tiger Reserve supports diverse habitats, including tropical rainforests (Image 1), subtropical forests, and alpine meadows. The dense tropical rainforests include vegetation such as Dipterocarpus turbinatus, Dipterocarpus retusus, Shorea assamica, Shorea robusta, Castanopsis roxburghiana, and bamboo groves. Namdapha National Park and Tiger Reserve is a crucial component of the Indo-Burma biodiversity hotspot and supports rare and endangered species such as Snow Leopard Panthera uncia (Schreber, 1775), Clouded Leopard Neofelis nebulosa  (Griffith, 1821), and Asian Elephant Elephas maximus (Linnaeus, 1758).

 

Methods

The field survey was conducted over a span of eight days from 10–17 October 2024, with the investigation focusing on riverbanks, forest trails, narrow streams, and waterfall habitats. Random field sampling was undertaken daily from 0500–1900 h along these habitats. Species identification was based on photographic evidence captured using a Nikon D3300 DX-format DSLR with an 18–55 mm lens. The identification of species and confirmation was carried out in consultation with literature (Payra et al. 2017). No physical specimens were collected in strict adherence to forest norms in complete compliance with the Indian Wildlife Protection (Amendment) Act, 2022.

 

Observations and findings

Inclusive of the findings presented in this study, the field survey has resulted in several re-discoveries (Mahesh 2025; Upadhaya 2026). Totally 17 Odonata species were documented during 12 samplings. These include Trithemis aurora Burmeister, 1839, Neurothemis fulvia (Drury, 1773), Orthetrum glaucum (Brauer, 1865), Echo margarita Selys 1853, Aristocypha spuria Selys, 1879, and Neurobasis chinensis (Linnaeus, 1758). As a highlight among these observations, a single male specimen of Gynacantha khasiaca (Image 2, 3 & 4) was observed on 16 October 2024 around 08.00 h on a cloudy day along the Miao-Vijaynagar road (altitude of 600 m) within the Namdapha National Park and Tiger Reserve (Image 5). The male was initially observed rapidly patrolling along the road edge and hovering while defending its territory. It subsequently resumed pendent perching in the vertical hanging posture, within a shaded area surrounded by dense vegetation.

 

The systematic position of Gynacantha khasiaca Maclachlan, 1896 is represented below (Martin 1909).

Phylum: Arthropoda

Class: Insecta

Order: Odonata Fabricius, 1775

Suborder: Anisoptera Selys, 1854

Family: Aeshnidae Leach, 1815

Genus: Gynacantha Rambur, 1842

Species: Gynacantha khasiaca Maclachlan, 1896

 

The head was pale blue to olive-green eyes, olive-brown labrum and labium, and a light green frons with a distinct black ‘T’-shaped marking. The thorax was bright green with two thick blackish-brown stripes on each side. The wings were hyaline with an amber tint at the base; pterostigma covers 4–5 cells. The forewing discoidal cells consisted of five cells, while hindwing discoidal cells ranged 4–6. The abdomen measured about 47–51 mm, with segments 8–10 being entirely black. The anal appendages were black; with inferior appendages about two-thirds the length of the superior appendages (Martin 1909).

 

Discussion

Due to limited knowledge regarding distribution, seasonality, and habitat specificity, G. khasiaca is classified as ‘Data Deficient’ by the IUCN Red List of Threatened Species (Mitra et al. 2010). Outside India, it has been documented in Nepal (Vick 1989), Myanmar (Fraser 1936), and Bangladesh (Khan, 2015b). In India, as per the portal of indianodonata.org, G. khasiaca has been recorded from the states of Maharashtra in 2020, West Bengal during 2014 and 2015, and in Assam during 2019 (Sawant et al. 2026). As per research publications, G. khasiaca has been documented from the states of West Bengal (Payra et al. 2017; Mitra 2002), Uttarakhand (Prasad & Sinha 2010) and exclusively from northeastern states such as Meghalaya (McLachlan 1896; Fraser 1924; Kimmins 1969), Assam (Laidlaw 1923; Fraser 1936; Payra et al. 2017), and Arunachal Pradesh (Laidlaw 1914). Reports also indicate this species has also been documented in parts of Nagaland, but these records remain scarce and largely unverified.

As per the portal of indianodonata.org, it can be highlighted that the most recent sighting for entire India is from Majgaon, Sindhudurg in Maharashtra during July 2020 and when only north-eastern states are highlighted, the last confirmed sighting was way back in September 2019 from Orang National Park, Sonitpur in Assam (Sawant et al. 2026). When only research repositories are referred to, it was found that the last confirmed record in India was in 2017, at Purba Medinipur in West Bengal. If only northeastern states are considered, then the last confirmed record was in 2015 from Khalingduar Forest in Assam (Payra et al. 2017). These are located 1,710 km and 605 km away from the present site of discovery, respectively. Hence, in this context, the re-discovery of Gynacantha khasiaca in Namdapha National Park and Tiger Reserve (Arunachal Pradesh) is highly significant, considering that the species was last reported over a century ago from Arunachal Pradesh at Abor Hills (Laidlaw 1914). Abor Hills is also approximately about 600 km away from location of present discovery. Even, the nearest location from which a record of Gynacantha khasiaca has been observed to-date is about 400 km away at Deopahar, Golaghat Assam (Payra et al. 2017), hence extending its known range.

Earlier odonate surveys undertaken in Arunachal Pradesh by researchers (Ram & Prasad 1999; Mitra 2002) and the forest department (2018 & 2020 pers. comm.) have not recorded G. khasiaca. Conclusively, it can be hence stated that this sighting at Namdapha National Park and Tiger Reserve marks the first verifiable recent record of G. khasiaca from Arunachal Pradesh in a 100 year’s timeline. The lack of confirmed records from similar habitats highlights its rarity and the possibility that G. khasiaca has a patchy or highly specialized distribution. It may also be attributed to limited surveys in the remote forested regions, habitat degradation, climate shift and low detection probability as a species (Theischinger et al. 2020; Aadarsa et al. 2021).

 

Biodiversity implications and conservation concerns

Gynacantha khasiaca has been documented from nine scattered localities across Assam and West Bengal, occurring at elevations ranging 7–377 m. Of these records, seven were from sites located near forested areas, essentially representing forest-edge habitats with human encroachment and settlements. The remaining two sightings were reported from dense forest habitats at Deo Pahar and the Murti River-bed. The species was mostly encountered during the day and crepuscular hours (1017–1850 h), and predominantly in lowland areas. The observations indicate that this species depends on structurally intact riparian microhabitats to maintain viable populations. Given the sparse records and fragmented distribution, additional studies are necessary to better understand its habitat specificity, breeding ecology, and seasonal activity patterns.

 

Conclusion

This study presents the first record of Gynacantha khasiaca after 110 years from the Indian state of Arunachal Pradesh, hinting at the scope for further inter-species and intra-species discoveries amidst the less explored ecologically rich Namdapha National Park and Tiger Reserve. Invariably, this communication also highlights conservation need of a potential biodiversity hotspot.

 

 

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