DIVERSITY AND DISTRIBUTION OF AQUATIC INSECTS IN A TROPICAL SMALL STREAM OF SOUTH IÑDIA BETWEEN 1996-1997 AND 2006-2007: IS IT THE CONSEQUENCE OF ANTHROPOGENIC IMPACT OR CLIMATE CHANGE OR BOTH?

Deforestation, construction of dams for agro-electric projects, urbanization, and industrialization are the different factors of globalization and are lead to modify the natural structures, in developing countries. Aquatic insects are indicators of habitat and climate change in streams. Therefore, we examined the diversity and distribution of aquatic insects in a small stream of Sirumalai hills, south India between 1996-1997 and 2006-2007. In the sampling period of 2006- 2007, air and water temperature had slightly higher than that of 1996-1997. The maximum number of taxa was obtained during the month of October in 1996-1997 and November in 2006-2007. The percentage of shredders and scrapers were increased and collector-filterers, collector-gatherers and predators were decreased during 2006-2007. BMWP and ASPT scores were higher in the sampling period of 1996-1997 than’2006-2007. Both global climate change and anthropogenic impact influence the community structure of aquatic insects.