Start Date: Mar 03, 2008
End Date: Mar 02, 2013
This agreement will determine the effect of Bt crop production on the population genetics of bollworm, tobacco budworm, and fall armyworm. Specific issues will be: 1) a better overall understanding of gene flow and population structure for the pests; 2) Bt-resistance allelic frequency estimates over time; 3) the impact of changing refuge strategies and dynamic agroecosystems on managing resistance to Bt; and 4) the impact of Bt-suppressed population densities on insecticide resistance, e.g. the recent pyrethroid resistance in bollworm. The cooperator will be actively involved in all phases of this research including the collection of test insects from across the U. S. Cotton Belt. Pyrethroid resistance assays will be conducted in the cooperator's laboratory. Insect tissue will then be sent to the USDA-ARS for use in genetic marker analysis and carbon isotope analysis. Other technologies (e.g. secondary plant chemical detection in insect tissue and oxygen and nitrogen isotope analysis) will be used as they become available to further understand the population ecology of the pests in relation to Bt resistance management. Landscape population models of Lygus lineolaris and Helicoverpa zea will be adapted from existing Bt-resistance evolution models to organize information and prioritize research on polyphagous pests impacting the economics and ecology of Bt cotton systems in the Mississippi Delta.