
Aquatic insect diversity of Rajaji National Park has been monitored for a period of twelve months. Some of the hydrological attributes were measured in continuity of one month interval. Aquatic insects were sampled from four sampling sites (S1, S2, S3 and S4) of Song and Suswa river of Rajaji National Park. The study revealed that some of the physico-chemical parameters in addition to nature and size of substrate have their significant impact on aquatic insect diversity. The diversity of benthic macro invertebrates have found to be high in winter months comparatively due to low turbidity, high water transparency, moderate water temperature, high dissolved oxygen and low water velocity. The abundance of aquatic insects were also associated with the high primary production during winter season. Some suggestions were also made for the conservation and management of the diversity of aquatic insects dwelling the Song and Suswa rivers of Rajaji National Park.