In this work we integrated, refined and validated molecular tools for Bt resistance monitoring in Helicoverpa spp. in Australian cotton fields.

1.      We have simple easy to use workflows for Bt resistance allele detection that are very sensitive in a variable genome

2.      A first pass population genetics study of Helicoverpa armigera, including the northern cotton growing regions and over time reveals no genetic differentiation at any spatial or temporal scale investigated here

3.      We have identified putative Bt resistance alleles in laboratory-maintained, field-derived Bt resistant insect colonies using a quantitative genetics approach. Many of these live insect colonies are now being maintained at CSIRO Black Mountain.

The molecular tools used here offer new insights into the genetic complexity of Bt resistance in Helicoverpa spp in Australian cotton systems, indicating the RMP strategies are highly effective at reduce the selection pressure on insects and preventing the evolution of resistance. However, in the context of Bt resistance, these molecular tools must be used in conjunction with traditional bioassays or phenotype-based resistance monitoring, as they are not effective at identifying novel Bt resistance causing mutations.