Gene editing to enhance pesticide resistance in a beneficial predatory mite.

Successful integrated pest management (IPM) often depends on a suite of control strategies that are compatible with one another. The predatory mite Neoseiulus californicus (Acari: Phytoseiidae) is a key biological control agent of spider mites (especially Tetranychus spp.) and other diminutive, yet important arthropod pests of agriculture. However, like many natural enemies, N. californicus is highly sensitive to chemical pesticides, limiting its overall effectiveness in the field. Here, we used CRISPR/Cas9 gene editing and Receptor-Mediated Ovary Transduction of Cargo (ReMOT Control) to create N. californicus harboring loss-of-function mutations in the nicotinic acetylcholine receptor α6 subunit (nAChRα6), the target of the pesticide, spinetoram. The resulting knockout strain (FZ-α6KO) exhibited a 23-fold increase in resistance to spinetoram compared to its parental strain. Inheritance of resistance to spinetoram in FZ-α6KO was autosomal, recessive, and tightly linked with the nAChRα6 gene. We demonstrate that by pairing gene editing with ReMOT Control, extremely small and fragile beneficial arthropods can be genetically manipulated. These results suggest that genetic modification to enhance pesticide resistance in beneficial predatory mites could improve the compatibility between the use of pesticides and biological control organisms.