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Abstract: Genetically modified (GM) crops are used extensively worldwide to control diploid agricultural insect pests that reproduce sexually. However, future GM crops will likely soon target haplodiploid and parthenogenetic insects. As rapid pest adaptation could compromise these novel crops, strategies to manage resistance in haplodiploid and parthenogenetic pests are urgently needed. Here, we developed models to characterize factors that could delay or prevent the evolution of resistance to GM crops in diploid, haplodiploid, and parthenogenetic insect pests. The standard strategy for managing resistance in diploid pests relies on refuges of non-GM host plants and GM crops that produce high toxin concentrations. Although the tenets of the standard refuge strategy apply to all pests, this strategy does not greatly delay the evolution of resistance in haplodiploid or parthenogenetic pests. Two additional factors are needed to effectively delay or prevent the evolution of resistance in such pests, large recessive or smaller non-recessive fitness costs must reduce the fitness of resistance individuals in refuges (and ideally also on GM crops), and resistant individuals must have lower fitness on GM compared to non-GM crops (incomplete resistance). Recent research indicates that the magnitude and dominance of fitness costs could be increased by using specific host–plants, natural enemies, or pathogens. Furthermore, incomplete resistance could be enhanced by engineering desirable traits into novel GM crops. Thus, the sustainability of GM crops that target haplodiploid or parthenogenetic pests will require careful consideration of the effects of reproductive mode, fitness costs, and incomplete resistance. [Copyright &y& Elsevier]

Abstract: Wolbachia induce cytoplasmic incompatibility (CI) in some host insect species. Similar to the sterile insect technique, releasing CI Wolbachia-infected males into an uninfected population can possibly decrease the insect population. Many species of leafminers are known to be cosmopolitan insect pests. CI Wolbachia-infected species that are closely related to leafminers are important for transfecting other leafminer species. In this study, we found a Wolbachia-infected strain of Liriomyza trifolii (Burgess) (Diptera: Agromyzidae) and a naturally occurring Wolbachia-free strain. In addition, we developed an antibiotic-treated Wolbachia-free strain. The crossing experiments revealed that only the eggs resulting from the mating of infected male and Wolbachia-free female failed to hatch almost completely. The Wolbachia strain that showed strong CI and perfect vertical transmission in L. trifolii may have application in insect pest control. [Copyright &y& Elsevier]