Evaluation of GS-omega/kappa-Hxtx-Hv1a and Bt toxins against Bt-resistant and -susceptible strains of Helicoverpa zea (Boddie) and Spodoptera frugiperda (J.E. Smith)

Abstract

Helicoverpa zea and Spodoptera frugiperda are destructive insect pests of cotton and corn. Both have evolved practical resistance to transgenic crops producing Bacillus thuringiensis (Bt) toxins in the United States. GS-omega/kappa-Hxtx-Hv1a (ω/κ-Hv1a) is a novel biopesticide derived from spider venom with activity against lepidopteran pests. The efficacy of ω/κ-Hv1a is dependent on combining it with a facilitator product such as a Bt-based insecticide. However, it is unknown if ω/κ-Hv1a can be an alternative for the management of Bt resistance. In this study, we tested the effect of ω/κ-Hv1a alone or in the presence of Bt toxins against susceptible and resistant H. zea and S. frugiperda.