Assam: New spiny ant species discovered in Garbhanga forest, named ‘Assamese Spiny Ant’
Guwahati: In a significant addition to Assam’s biodiversity records, researchers have discovered a new species of spiny ant in the Garbhanga Reserve Forest on the outskirts of Guwahati — highlighting the ecological value of urban forest fragments.
The species, Polyrhachis garbhangaensis sp. nov., has been named after its place of discovery and is proposed to be known as the “Assamese Spiny Ant.” The study has been published in Asian Myrmecology (2026).
The team behind the discovery includes:
- Ankita Sharma – Animal Behaviour and Cognition Programme, National Institute of Advanced Studies (NIAS), Bengaluru
- Paul Antony Mangaly – NIAS, Bengaluru
- Suraj Kumar Singha Deo – NIAS, Bengaluru
- Sangavi D – NIAS, Bengaluru
- Anindya Sinha – NIAS, Bengaluru, and the Coexistence Studies Group, Trans-Disciplinary University of Health Sciences and Technology
A Third of Its Kind in India
The newly identified ant belongs to the Polyrhachis mucronata species group under the subgenus Myrmhopla. It represents only the third known Indian species in this group.
India records 71 species of the genus Polyrhachis, with Assam alone accounting for 21 of them — making it one of the country’s hotspots for spiny ant diversity.
Discovered in a Forest Under Urban Pressure
The ant was collected in August 2023 through pitfall traps set along a stream transect in the Garbhanga Reserve Forest, a 117 sq km green belt forming part of Guwahati’s southern forest landscape and contiguous with the Rani Reserve Forest.
The discovery emerged from a broader research project examining how urbanisation impacts ant and spider diversity in South Guwahati.
What Makes It Unique?
The new species stands out from its closest Indian relatives due to a bright yellowish-orange abdomen (others are black), moderately long, curved petiolar spines, and a shiny yet distinctly sculptured head. The holotype worker measures about 5.6 mm in total length.
An Ecological Twist
Researchers also found an ant-mimicking spider (Peng sp., family Corinnidae) in the same habitat — suggesting possible ecological dominance of the new ant species and raising interesting questions about predator–prey dynamics.
Why This Discovery Matters
Beyond adding a new species to science, the study updates the identification key for the Indian members of the Polyrhachis mucronata group and underscores the critical biodiversity value of fragmented urban forests like Garbhanga.
As Guwahati expands, the finding serves as a reminder: even forests on a city’s edge can harbour species unknown to science — waiting to be discovered.