Diversity and Composition of Aquatic Insects in Three Perennial Rural Ponds of Ramnagar-I Block, East Midnapore, West Bengal, India

This investigation focused on the diversity of aquatic insects in three perennial rural ponds located in the Ramnagar-I block of East Midnapore, West Bengal, India. Insects comprise about four-fifths of the world’s fauna and are recognized as the most diverse and successful group within the animal kingdom. Many of these insects spend at least part of their life cycle in water, making them aquatic insects. They represent a vital component of the littoral fauna in aquatic ecosystems and play a crucial role in the trophic structure and functions of cultivable water bodies. From March 2023 to February 2024, a total of 1,637 individuals were recorded, belonging to 6 orders, 15 families, and 29 genera across the three ponds (P1, P2, and P3). The rich assemblage of aquatic insects found in these ponds suggests a relatively healthy and stable ecosystem, supported by good water quality. The dominant families observed included Gerridae (14.91%), Coenagrionidae (18.51%), and Nepidae (13.62%), highlighting their significant ecological roles at these sites. Seasonal variations in species richness were apparent across the ponds. The highest numbers of individual occurrences were recorded during the post-monsoon season (P1: 12.16%, P2: 10.63%, P3: 9.22%), whereas the lowest were noted in winter (P1: 7.27%, P2: 6.17%, P3: 5.19%). Among the recorded species, the most dominant taxa included Baetis sp. (Ephemeroptera), Gerris spinolae (Hemiptera), and Ischnura senegalensis (Odonata). The seasonal environmental variations largely account for the diversity of insects in the three ponds, as factors such as temperature, dissolved oxygen, and vegetation cover significantly influence species abundance and distribution.