Arunachal Pradesh, one of the world’s richest biodiversity regions, has witnessed a landmark scientific breakthrough. An Indo-German research team has discovered 15 species of Stenus beetles new to science in the waterfalls and forests of the Eastern Himalayas. This marks one of the largest recent additions to the insect fauna of the region, raising the total number of Stenus species recorded from Arunachal to 103, including 21 species new for India and 44 new for the state.
The findings were published in Linzer Biological Contributions by eminent taxonomist Dr Volker Puthz, in the article “Steninae from Arunachal Pradesh, India.” Several species have been named in honour of key researchers: Stenus gogoii, S dobiami, and S sonui for Rajiv Gandhi University’s entomology team, and S oliver and S tobias for German collaborators Prof Oliver Betz and Tobias Mainda.
The team expressed gratitude to indigenous communities — Nyishi, Sherdukpen, Bugun, Memba, and Adi — whose support was described as “indispensable” to the success of the project.
The collaboration began in 2021 when Prof Betz contacted RGU to explore insect diversity. A formal MoU was signed in May 2023 between RGU and the University of Tübingen, supported by the German Research Foundation (DFG). Between December 2024 and March 2025, four major expeditions across Pakke-Kessang, West Kameng, and Shi-Yomi yielded specimens collected with aspirators, sieves, and sweep nets — many previously unknown to science.
The newly recorded beetles, measuring 1.9–6.5 mm, belong to the genus Stenus, part of the rove beetle family — one of the most diverse insect groups with over 63,000 species worldwide. Known for their shortened wing covers, strong jaws, and unique extendable mouthparts, Stenus beetles are tiny predators that play a crucial role in ecosystems.
Researchers believe many more species await discovery in Arunachal, and hope this Indo-German success will inspire renewed biodiversity exploration across the Eastern Himalayas.
