High levels of biological activity of Cry1Ac protein expressed on MON 87701 × MON 89788 soybean against Heliothis virescens (Lepidoptera:Noctuidae)

Background Genetically modified MON 87701 × MON 89788 soybean ( Glycine max ) that expresses the Cry1Ac and EPSP ‐synthase proteins is a new Integrated Pest Management ( IPM ) tool for controlling Heliothis virescens in Brazil. To Support Insect Resistance Management ( IRM ) programs and understand the value of this event for IPM , we conducted laboratory and field studies to assess the biological activity of Cry1Ac protein expressed on Bt soybean against this insect pest . Results Heliothis virescens was highly susceptible to purified Cry1Ac protein [ LC 50 ( FL 95%) = 0.026 (0.021–0.033) µg Cry1Ac mL –1 diet]. In bioassays with freeze‐dried MON 87701 × MON 89788 soybean tissue diluted 25 times in an artificial diet, there was 100% mortality of H. virescens . In bioassays with leaf disc, young trifoliate, flower buds, pods and high artificial infestation under greenhouse condition, MON 87701 × MON 89788 soybean showed a high level of control against H. virescens . Moreover, larvae from first through fifth instar were highly susceptible to MON 87701 × MON 89788 soybean . Conclusions The MON 87701 × MON 89788 soybean provides an effective alternative in controlling Heliothis virescens and complies with the concept of high‐dose for IRM programs. © 2013 Society of Chemical Industry