CONCLUSION

The present study reveals that the aquatic insects play a vital role in the ecological structure and ecosystem functions of Aghanashini River.  The good representation of pollution sensitive taxa like Isonychia, Helicopsyche, Isca, Petersula, and Ephemerella emphasizes the importance of pristine rivers and streams, like Aghanashini and its tributaries, still present in the Western Ghats, one of the global biodiversity hotspots, increasingly falling prey to anthropogenic pressures.  Aquatic insects not only enhance stream nutrient cycling through their feeding strategies, but also support communities of larger organisms like fish, frog and others. The water-bodies of Western Ghats being the main centres of especially aquatic faunal endemism, such as of fishes and amphibians, biomonitoring of more number of streams and rivers, using aquatic insect community, and working for their holistic conservation, incorporating also the catchment area natural vegetation, deserve to be prioritized by conservationists (Martin, 2000; Sreekantha et al., 2007; Gururaja et al., 2008 and Chandran et al., 2010).   The integrity of stream insect communities heavily relies upon the structural integrity of the streams and processes associated with their physical habitats which stretch even much beyond them.