Biodiversity of Aquatic Insects in Kalsa River (Chanfi) of Nainital District, Uttarakhand, India

Aquatic insects are the most species-rich group that inhabit freshwaters. They are connected to water by at least one life stage, usually that of the larvae, and some spend their entire life in freshwater habitats. The majority of aquatic insects’ larvae develop in water; while adults emerge and spend their lives primarily in terrestrial environments where they mate, disperse and in some cases feed. Aquatic insects are important components of stream food webs and are greatly impacted by anthropogenic disturbances, including urbanization. A study was conducted in Kalsa River, Nainital District to understand the diversity of insects in the area by using sweep-net method and analysis by respected equation and indexes. The study recorded 259 numbers of individuals which divided into 4 orders, namely Lepidoptera, Hymenoptera, Coleoptera, Diptera, and Orthoptera. Trichoptera, Odonata and Hemiptera was dominant order, were as Diptera is least dominant among all the reported orders. The Shannon-Wiener diversity index was highest in site, at (H’=1.79). Evenness was highest at (E=0.38), and the Margalef’s Richness Index was (d=1.50). Overall, this study offers a novel method for predicting aquatic insect distribution with high geographic resolution, which aids in the protection of river diversity in the face of anthropogenic and climatic change also this study aimed to identify aquatic insects’ species in and provide baseline information for future research.