Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) of Northeast India – Patterns and gaps in discovery

True dung beetles belonging to the sub-family Scarabaeinae, a group with over 6000 species known worldwide, play an important role in biological pest control, soil fertilization, and several other ecosystem services. At present, the Northeast India biogeographic region, the meeting point of two world biodiversity hotspots, has reports of 206 species of Scarabaeinae. State-wise species reports from this group indicated that certain states like Meghalaya and Arunachal Pradesh have relatively higher richness compared to other states like Nagaland and Mizoram. The species discovery curve of Northeast Indian Scarabaeinae indicated two distinct periods of descriptions in 1931 and 2000, apart from which the rate of discoveries in the region has been slow. Body size and range of the species were weak indicators of the date of description and pattern of species discovery in the region. Mapping of the type localities of the species suggests that most of the discoveries were around major cities with easier accessibility, suggesting gaps in the systematic studies conducted in the region. Incomplete distribution information, especially of ecologically important taxa like dung beetles leads to several challenges regarding the lack of clarity on their ecology and conservation status. Our results thereby stress on the need for systematic taxonomic inventorying and long-term monitoring of ecologically important, yet underexplored taxa such as Scarabaeinae in the region.