Diversity, peak period of visit and relative abundance of insect forager complex with special reference to syrphid flies on rapeseed

Abstract

Among all the insect foragers A. cerana was found to be more dominant (9.38%) and their peak period of visit was in between 09.00 - 10.00 hours. It was also observed that all the foragers were more active during the forenoon hours. The species richness, dominance and distribution of Syrphid flies on rapeseed (var. TS-38) were also recorded during the study. A total of 27 foragers belonging to 4 orders, 8 families and 27 species were recorded during our experiment and among the 27 species of insect foragers 15 species of them were recorded from Syrphidae families belong to Dipteran order. The syrphid species diversity index (2.59), evenness indices (0.39) and species richness (15) were recorded from the rapeseed ecosystem. The dominance index (d) recorded was Episyrphus balteatus (0.15) followed by Eristalinus arvorum (0.11).