Water Quality Assessment with Biotic Index Based on Abundance and Diversity of Aquatic Insects in a Hilly Stream, Bangladesh

Study of stream insect fauna provide valuable insights into aspects the channel ecosystem. The present study was conducted to investigate aquatic living community, abundance and diversity in a hilly stream, Balukhali chora Chittagong University campus determine water quality. insects were collected with bottom dredge net from edge benthic regions Riffle zone Pool January 2018 December 2018. Insects sampled using standard entomological method determined their tolerance value. A total 2535 recorded, belonging six orders, 30 families 45 genera. ratio higher all months excepting April, May, June October. orders Ephemeroptera, Odonata Diptera abundant zone, while Hemiptera, Coleoptera Lepidoptera zone. On basis Biotic Index, most dominating Hemiptera indicated good quality, though dipteran genus Chironomus spp. poor quality some months. community structure two zones that overall very good. Both manmade natural interruption occurred due human settlement, agricultural runoff disasters. know which stream.