V3I9P28

Entomofaunal Diversity and Ecological Roles of Aquatic Insects 

Konda Limbadri^1*

Abstract

Aquatic insects constitute one of the most diverse, abundant, and ecologically important components of freshwater ecosystems. They occur in streams, rivers, ponds, lakes, reservoirs, marshes, swamps, wetlands, and other aquatic habitats, where they participate in almost every major ecological process. Many insect groups spend their larval or nymphal stages in water and their adult stages in terrestrial environments, creating an important ecological connection between aquatic and terrestrial ecosystems. Major aquatic insect groups include mayflies (Ephemeroptera), stoneflies (Plecoptera), caddisflies (Trichoptera), dragonflies and damselflies (Odonata), aquatic bugs (Hemiptera), aquatic beetles (Coleoptera), mosquitoes and other flies (Diptera), alderflies, dobsonflies and fishflies (Megaloptera), and several other less diverse groups. Freshwater insects occupy diverse functional feeding groups, including shredders, collectors, scrapers, grazers, filter feeders, herbivores, detritivores, and predators. Through these activities they contribute to decomposition, nutrient cycling, energy transfer, primary and secondary production, and regulation of aquatic food webs. They are also an important food source for fish, amphibians, birds, bats, spiders, and other predators. Because many aquatic insects respond rapidly to changes in dissolved oxygen, temperature, nutrients, toxic substances, habitat structure, and flow conditions, they are widely used as biological indicators of freshwater environmental quality. However, aquatic insect communities are increasingly threatened by pollution, habitat modification, flow alteration, pesticides, invasive species, climate change, and wetland loss. Conservation of aquatic insect diversity therefore requires integrated management of freshwater habitats, riparian vegetation, water quality, and catchment-level land use. This article reviews the diversity, distribution, functional roles, ecological significance, bioindicator value, major threats, and conservation needs of aquatic insects, with particular relevance to freshwater ecosystems in India.

Keywords:

Aquatic insects, entomofaunal diversity, freshwater biodiversity, ecological roles, macroinvertebrates, bioindicators, food webs, nutrient cycling, conservation