Aquatic Insect Diversity and Their Role in Natural Pest Regulation in Semi-Arid Paddy Agroecosystems of Telangana, India

Rice agroecosystems function as temporary wetland habitats that support diverse aquatic insect communities, which play a crucial role in ecosystem functioning and natural pest regulation. The present study was conducted in paddy fields of Kerchipally and Velvarthi villages, Valigonda Mandal, Yadadri Bhuvanagiri district, Telangana, India, to assess aquatic insect diversity and evaluate their role in pest suppression. Sampling was carried out during the Kharif season (June to October 2023) across three crop growth stages (vegetative, reproductive, and harvesting) using standard dip-net and sweep-net methods. A total of 40 aquatic insect species belonging to five orders and 18 families were recorded. Diptera dominated the community (35 %), followed by Hemiptera (22.5 %), Coleoptera (17.5 %), Odonata (15 %), and Ephemeroptera (10 %). Diversity indices showed significant variation across crop stages, with the highest Shannon–Wiener index (H′ = 3.12) observed during the reproductive stage, indicating optimal habitat stability and resource availability. Functional feeding group analysis revealed dominance of collectors (40 %), followed by predators (47.5 %) and grazers (12.5 %), reflecting a detritus-driven ecosystem with well-structured trophic interactions. Pest density decreased from 68 ± 5.2 individuals m⁻² in the vegetative stage to 25 ± 2.6 individuals m⁻² during the harvesting stage, corresponding with increased predator abundance. A significant negative correlation (r = –0.72, p < 0.05) between predator abundance and pest density confirmed the role of aquatic insects as effective biological control agents. The study highlights the ecological importance of aquatic insects in pest regulation and emphasizes the need for biodiversity-based management practices and reduced pesticide use for sustainable rice production.