An Indo-German research team has discovered 15 species of Stenus beetles new to science in Arunachal Pradesh, making it one of the largest recent additions to the insect fauna of the Eastern Himalayas. The discoveries bring the total number of Stenus species recorded from the state to 103. The findings include 21 species new to India and 44 new to Arunachal.

The research was the outcome of a collaboration between Rajiv Gandhi University (RGU) and the University of Tübingen, initiated in May 2023 and supported by the German Research Foundation (DFG), with permissions from the National Biodiversity Authority and the PCCF (Wildlife), Arunachal.

The journey began when Prof Oliver Betz, a world-leading expert on rove beetles, contacted RGU in 2021 to explore the insect diversity of Arunachal. Between December 2024 and March 2025, researchers conducted four extensive field expeditions across Pakke-Kessang, West Kameng and Shi-Yomi districts.

India had around 167 described Stenus species, according to previous scientific reports. Researchers believe that many more species await discovery in Arunachal, and hope that the success of this Indo-German collaboration will inspire renewed efforts towards biodiversity exploration across the region.

As a biodiversity hotspot, such far-reaching research and documentation are important. More such research and collaborations should be encouraged and supported in the state, because documentation is an important first step towards planning and implementing effective conservation policies.

This is particularly important as Arunachal is set to witness massive infrastructure development that could severely disturb its fragile ecology. Before species and ecosystems are lost, there is a need to know what exists, where it exists and how vulnerable it is. Research and documentation can provide that crucial baseline for making informed decisions about development and conservation.