Study on seasonal variation of aquatic insects in a lotic ecosystem of Guwahati City, Assam, India

The present study on aquatic insect diversity reveals presence of 14 families and 15 genus of aquatic insect community in different seasons in a lotic ecosystem of Guwahati City, Assam. Order Diptera with 4 families was numerically the most abundant group constituting 49% of the total aquatic insects. The Baetis sp. belonging to order Ephemeroptera and Neuroplecsis larva of order Trichoptera were recorded during the investigation. The highest population of aquatic insect was recorded during the winter season followed by pre-monsoon and post monsoon season. The lowest and highest numbers of insects were recorded in the month of July and February respectively. The study revealed the presence of two dominant and six subdominant genus in the river ecosystem.