Guwahati: Scientists have discovered a dazzling new species of damselfly deep within the misty forests of Arunachal Pradesh, where mountain streams snake through thick, evergreen canopies. Named Caliphaea sinuofurcata and proposed to be called the “Bearded Bronzeback,” this stunning insect marks the first time a species from the genus Caliphaea has been newly described from India in over 165 years.
A team of researchers—Dattaprasad Sawant, Shantanu Joshi, Ujwala Pawar, Viraj Nawge, and Krushnamegh Kunte—made the discovery during biodiversity surveys in the Upper Siang and Lower Dibang Valley districts of Arunachal Pradesh. Their work, published in the May 2025 issue of Zootaxa, is based on three specimens: two males and one female, collected from remote mid-elevation forests near Tuting and Hunli.
While the genus Caliphaea is known from parts of Southeast Asia and China, only one species — C. confusa — was previously recorded in India. However, detailed examination of the specimens’ morphology revealed a distinct new species, especially noticeable in the male’s unique caudal appendages. The name sinuofurcata — from the Latin words sinuosus (wavy or sinuous) and furcatus (forked) — refers to the twisted, bifurcated shape of the paraproct, a tail structure used for mating and species recognition.
“This is the first description of a new species from the genus Caliphaea within India, but there have been new species from other countries. Since there is only one species that occurs commonly in Northeast India (Caliphaea confusa), we initially assumed our individuals to belong to the same species. But close examination by Dattaprasad revealed that there were some important structural differences between the species we observed in Siang Valley and Caliphaea confuse,” Dattaprasad Sawant says.
What makes this species even more visually captivating is the presence of dense, black, beard-like bristles around the mouthparts of both males and females. These hair-like setae on the labium and labrum inspired the proposed English name — the Bearded Bronzeback. The damselfly gleams in metallic copper-green hues, with slender wings faintly tinted in brown, and a body adorned with subtle yellow and olive markings.
The researchers found the damselflies inhabiting small, rocky seasonal streams in broadleaf evergreen forests at elevations around 1200 to 1300 meters above sea level. Individuals were observed flying low and perching on vegetation near the water, in dappled sunlight. These habitats, often overlooked during large-scale surveys, harbour a surprising array of species waiting to be formally described.
This new addition is particularly significant because it is only the second species of Caliphaea ever recorded from India — the last one, C. confusa, was described over a century and a half ago. The discovery of C. sinuofurcata not only expands the known range of the genus but also raises important questions about how many similar species might be hidden across northeastern India and Southeast Asia.
The researchers note that previous Indian records of C. confusa may include misidentified individuals. Historically, little attention was paid to the fine structures of the tail appendages — a key trait for distinguishing Caliphaea species. This discovery highlights the importance of re-examining old museum specimens and supplementing morphological studies with genetic data to clarify species boundaries.
Moreover, the discovery comes amid growing concern for habitat conservation in Arunachal Pradesh. Mid-elevation forest streams — the preferred habitat of the Bearded Bronzeback — are highly vulnerable to logging, road construction, and hydropower projects. The fact that a new and distinctive species has been found in such areas underscores their ecological importance and the urgent need to protect them.
Caliphaea sinuofurcata is the third new damselfly species described from the Upper Siang region in just the past year, alongside Yunnanosticta siangi and Devadatta adii. Together, these findings reflect the region’s extraordinary, yet underexplored, biodiversity, particularly for insects like dragonflies and damselflies, which are excellent indicators of ecosystem health.
With its shimmering armour and sinuous tail, the Bearded Bronzeback is a vivid reminder of the natural wonders that still await discovery in India’s last wild frontiers.
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