A.K. DHAWAN AND NEHA SHARMA

A field experiment was carried out to study of the diversity of arthropod communities in cotton at Entomological Research Farm, Punjab Agricultural University, Ludhiana during 2008-09. Comparison for arthropod diversity was made between RCH134BGI, RCH134BGII and Non Bt using the Shannon and Weaver diversity indices. Arthropod diversity was higher during the vegetative phase as compared to the reproductive phase of crop growth. Predatory arthropods and casual visitors were higher in Not Bt cotton and non target pests were higher in Bt cotton. Total diversity index was maximum in Non Bt followed by RCH134BGI and RCH134BGII. Hymenoptera sub community showed the maximum diversity. Natural enemies’ complex constituted one third of arthropod fauna on cotton crop. Higher diversity was attributed to greater equitability among the species while low diversity due to dominance of certain species.