Gene editing to enhance pesticide resistance in a beneficial predatory mite

Authors: LV, JING - Nanjing Agricultural University; YANG, YIHUA - Nanjing University; Fabrick, Jeffrey; WU, YIDONG - Nanjing University

Submitted to: Pesticide Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2025
Publication Date: 5/21/2025
Citation: Lv, J., Yang, Y., Fabrick, J.A., Wu, Y. 2025. Gene editing to enhance pesticide resistance in a beneficial predatory mite. Pesticide Biochemistry and Physiology. 212. Article 106466. https://doi.org/10.1016/j.pestbp.2025.106466.
DOI: https://doi.org/10.1016/j.pestbp.2025.106466

Interpretive Summary: Integrated pest management (IPM) involves the combination of diverse control strategies such as biological control, habitat manipulation, cultural practices, and use of host resistant crops, with the goal of removing only target pest organisms while minimizing the impact on the environment. The indiscriminate use of chemical pesticides often has negative effects, including impacts on off-target organisms, pest resistance, secondary pest outbreaks, and/or pest resurgence. Such pesticides also often have large negative impacts on arthropods that provide beneficial ecological services, including natural enemies such as predators. However, the use of pesticides can be successfully integrated into IPM programs, particularly when used only as needed and with compounds having relatively narrow spectrum of activity. Here, an ARS scientist at Maricopa, AZ and collaborators used gene editing to increase the ability of a beneficial, predatory mite (Neoseiulus californicus) to survive on pesticides commonly used to target key agricultural mite pests. Because such predatory mites are extremely small and considered refractory to methods typically used to perform gene editing in arthropods, a novel strategy was employed in which the gene editing cargo was delivered into adult females, allowing for the genetic changes to be made within their developing eggs prior to being laid. The results of this study show that not only can extremely small and fragile beneficial arthropods be genetically manipulated, but suggests that genetic modification can be used to enhance pesticide resistance in beneficial predatory mites, thereby improving the compatibility between the use of pesticides and biological control organisms.

Technical Abstract: 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 a6 subunit (nAChRa6), the target of the pesticide, spinetoram. The resulting knockout strain (FZ-a6KO) exhibited a 23-fold increase in resistance to spinetoram compared to its parental strain. Inheritance of resistance to spinetoram in FZ-a6KO was autosomal, recessive, and tightly linked with the nAChRa6 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.