Aquatic Insect Fauna and Diversity in Urban Fresh Water Lakes of Tripura, Northeast India

Freshwater lakes are integral part of urban ecosystem and provide numerous benefits to huma n beings directly or indirectly. An inventory was carried out to study the aquatic entomofauna, their diversity and distribution in three urban freshwater lakes of Tripura, northeast India during January to May, 2012. A total of 2159 individuals representing 31 species belonging to 23 genera, 15 families and 4 orders were recorded. Maximum of 30 species and 1191 individuals of aquatic insects were recorded in vegetation rich Maharaja Bir Bikram College Lake and minimum of 11 species and 215individuals were recorded in vegetation poor Laxminarayan Bari Lake. Insects belonging to the orders Hemiptera (32.26%) and Odonata (32.25%) showed higher species richness followed by those belonging to Coleoptera (25.81%) and Diptera (9.68%), respectively. Maximum diversity (H = 3.03) and least dominance (D = 0.06) and minimum diversity (H = 1.50) and maximum s s s dominance (D = 0.06) of aquatic insects was recorded in Maharaja Bir Bikram College Lake and Laxminarayan s Bari Lake, respectively. Richness estimators Chao 1 and Chao 2 provided the best predicted value of species richness. Three species are reported here for the first time from the state. Dominance of hemipteran and coleopteran insects suggested that urban lakes of Tripura are relatively less polluted.