Investigation on diversity studies during kharif 2015 and 2016, revealed that the relative density of aphids (48.26 & 35.58 %: Bt cotton 2015 & 2016; 39.28 & 34.60 %: non-Bt cotton 2015 & 2016) was the maximum on account of their numerical abundance. The relative density values for red cotton bug and thrips were next to that of aphids; while, the mealybug population had the lowest relative density value. Except for the mealybug, the seasonal mean of pest population was comparatively more in Bt cotton than in non-Bt cotton. The Shannon-Weiner and Simpson's diversity indices of insect pests were relatively higher for non-Bt cotton (1.64 and 4.28 during kharif 2015; 1.67 and 4.47 during kharif 2016) than in Bt cotton. Among the natural enemies, the relative density values for coccinellids (54.99 & 59.36 %: Bt cotton 2015 & 2016; 59.64 & 62.11 %: non-Bt cotton 2015 & 2016) was the maximum, followed by that for mantids and spiders; whereas, the relative density of syrphid larvae was the minimum during both the seasons in Bt as well as non-Bt cotton. The Shannon-Weiner and Simpson's diversity indices for natural enemies were relatively higher in Bt cotton (1.15 and 2.64 during kharif 2015; 1.06 and 2.36 during kharif 2016) than in non-Bt cotton.