Natural enemies were monitored throughout the season after insecticidal applications (acephate) vs. no applications to cotton just prior to the bollworm flight in mid-July. Large one-half acre replicated plots were utilized under two management scenarios: conventional cotton with a pyrethroid (Karate^®;) for bollworm control and B.t. cotton with supplemental control using a spinosyn (Tracer^®;). These early applications controlled plant bugs and disrupted natural enemies causing season-long reductions in geocorids and ants, the most abundant predacious arthropod groups. By late July, there was an average ca. 3.0 large bollworms per foot of row following three applications of Karate^®; to previously treated (disrupted) conventional plots compared with ca. 1.5 per foot following two applications to previously untreated (non-disrupted) plots. On the same date in B.t. cotton, there were 6X more bollworms (0.75/ft.) in disrupted plots after two applications of Tracer^®; than in non-disrupted plots after only one application. Obviously, use of "hard" insecticides just prior to the bollworm flight should be avoided in both conventional and B.t. cottons because their use destroys predacious arthropods, which can result in more crop damage even with more intensive spraying for bollworm control.