The most commonly accepted strategy for delaying insect resistance to transgenic crops is the high-dose plus refuge strategy. To augment this strategy and further reduce the likelihood of insect resistance developing, current and future transgenic insecticidal crops, such as VipCotTM, routinely express two or more insecticidal proteins targeting a similar pest spectrum. In the present study, we have evaluated the relative efficacy of two transgenic cotton events, COT67B (which expresses a Cry1Ab protein) and COT102 (producing Vip3A protein), against the tobacco budworm (Heliothis virescens) and cotton bollworm (Helicoverpa zea). Our data indicate that both COT67B and COT102 have high levels of activity against both species. COT102 and COT67B have been combined in our new insect-resistant cotton product, VipCotTM. The combined activity of the two component events in VipCotTM and Vip3A's unique mode of action will provide substantial benefit to cotton insect control and resistance management strategies.
