Evolutionary process modeling with Bayesian inference of Spodoptera frugiperda ballooning and walking dispersal in Bt and non-Bt cotton plant mixtures

Abstract

Transgenic crops expressing Bacillus thuringiensis Berliner (Bt) have been cultivated throughout the world as a great technological tool for developing integrated pest management. We hypothesized that artificial landscapes containing Bt and non-Bt cotton plants (Gossypium hirsutum L., Malvaceae) at small scales could influence dispersal by ballooning of Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae). We also simulated how ballooning dispersal combined with walking movement could impact resistance evolution in various scenarios of plant mixtures involving non-Bt and Bt cotton plants with high-dose and low-dose events. The ballooning frequency of Cry1F-resistant larvae in a treatment with non-Bt cotton as a natal plant and Bt cotton in adjacent sites was two-fold lower compared to when Bt cotton was the natal plant and non-Bt cotton was in the adjacent sites. Our model results suggested that the higher rate of walking movement associated with ballooning promoted faster resistance evolution in low-dose events, and contamination of Bt cotton fields with non-Bt cotton plants in a high-dose event showed the longest time to resistance. Therefore, a high rate of walking movement associated with ballooning negatively impacted the time for resistance to evolve in low-dose events.