Risk Assessment for Helicoverpa zea (Lepidoptera: Noctuidae) Resistance on Dual-Gene Versus Single-Gene Corn

摘要: Recent Environmental Protection Agency (EPA) decisions regarding resistance management in Bt-cropping systems have prompted concern some experts that dual-gene Bt-corn (Cry1A.105 and Cry2Ab2 toxins) may result more rapid selection for Helicoverpa zea (Boddie) than single-gene Bacillus thuringiensis (Bt)-corn (Cry1Ab toxin). The is Bt-toxin longevity could be significantly reduced with recent adoption of a natural refuge Bt-cotton (Cry1Ac concurrent reduction corn from 50 to 20%. A population genetics framework simulates complex landscapes was applied risk assessment. Expert opinions on effectiveness several transgenic cotton varieties were captured used assign probabilities different scenarios the At least 350 replicate simulations randomly drawn parameters completed each four assessments. Resistance evolved within 30 yr 22.5% no volunteer corn. When added this assessment, evolving declined 13.8%. planted 50% structured simulated, simultaneous both toxins never occurred yr, but 38.5% simulations, toxin present (Cry1Ab). simulated as products, 20% refuge, 3% simultaneously while 10.4% Cry1Ab/c toxin.