In 2000, supplemental insecticide applications to the B.t. cotton variety, Deltapine 451B/RR (contains a single gene for the production of CryIA(c) toxin), were evaluated to determine if improved Heliothine control could be demonstrated compared to untreated Deltapine 451B/RR. Insecticides evaluated were Steward 1.25SC, Tracer 4SC, Karate Z 2.09E, Asana XL
0.66EC, Vydate C-LV 3.77SL + Asana XL 0.66EC, Decis 1.5EC, and Baythroid 2EC. Under predominantly bollworm pressure in early July, all supplemental insecticide treatments reduced square damage. Under predominantly budworm pressure, during the remainder of the test, no differences among treatments were observed. Differences in live Heliothine larvae counts were not observed among treatments at any time. Supplemental applications of Tracer and Vydate + Asana significantly out yielded the untreated B.t. cotton control. This study suggests that benefits through increased yield can be obtained when appropriate supplemental insecticide applications, targeted at pests not adequately controlled by the CryIA(c) toxin, are utilized.