A Method to Suppress Bt Resistance in the Corn Earworm

Among the persistent threats to US agriculture the development of resistance against methods tocontrol pest populations ranks high. Polyphagous insects such as the corn earworm (Helicoverpazea) evolve these problematic resistance traits with particular rapidity and entire classes ofinsecticides are already ineffectual against H. zea.Most worrisome is the rise of resistance againstBt toxins as transgenic crops expressing these toxins are not only lucrative for the agriculturalindustry but condition the food security for society as a whole.It is clear that new agentstocombat Bt resistance are desperately needed. Lepidext has identified one such agent: ourtechnology is a strain of a sterilizing virus Hz-NV2 which we hypothesize will be a viablebiocontrol agent to manage outbreaks of Bt-resistant H. zea. This technology has advantages overalternate approaches to population control such as sterile insect technique and conventionalpesticide application and can be combined with IPM approaches such as refugia to retard theproliferation of resistance. The goal of this proposal is to validate this hypothesis with the followingobjectives: 1) perform experiments in our lab and insect rearing facility to assess the utility of ourtechnology to suppress Bt resistance in H. zea populations; 2) develop a statistical model tosimulate the application of Hz-NV2 to suppress Bt-resistant H. zea in the field. Together theseobjectives are critical to reach proof of concept that our technology can suppress H.zea outbreaks ofBt resistance in mixed populations of resistant and susceptible insects.