Diversity and Evenness of Aquatic Insects Asa Tool for Biological Assessment of Godawari Rivulets

Abstract

During the work, from Godavari Rivulets, altogether 47 taxa belonging to 9orders, 40 families and 33 genera were reported from 5 sampling sites. Amongthe total species collected species richness was highest of Odonata followed by Diptera, Ephemeroptera and Trichoptera, Coleoptera, Plecoptera, Hemipteraand Neuroptera respectively. As diversity and eveness of different sites were calculated, site I was found to be the most stable and site IV to be the least stable aquatic community on the basis of eveness value. Seasons were also found to affect the species richness of the aquatic insects.The species richness was found to be highest in Autumn (37 species),followed by Rainy (35 species), Winter (23 species) and Spring (16 species)respectively. NEPBIOS/ASPT Values were calculated to assess the water quality. For therivulets water quality-class II was obtained which means good except for site III for which water quality class I-II was obtained which indicates intermediate between excellent and good. There was variation in values that indicates the condition of the quality is deteriorating. NEPBIOS/ASPT Values were found slightly varying in different seasons in different sites. Human interference was frequently noticed at all the sites, which enhanced the degradation of natural resources including freshwater.