title: Does Drought Increase the Risk of Insects Developing Behavioral Resistance to Systemic Insecticides?
abstract: Increases in severity and frequency of drought periods, average global temperatures, and more erratic fluctuations in rainfall patterns due to climate change are predicted to have a dramatic impact on agricultural production systems. Insect pest populations in agricultural and horticultural systems are also expected to be impacted, both in terms of their spatial and temporal distributions and in their status as pest species. In this opinion-based article, we discuss how indirect effects of drought may adversely affect the performance of systemic insecticides and also lead to increased risk of insect pests developing behavioral insecticide resistance. We hypothesize that more pronounced drought will decrease uptake and increase the magnitude of nonuniform translocation of systemic insecticides within treated crop plants, and that may have two concurrent consequences: 1) reduced pesticide performance, and 2) increased likelihood of insect pests evolving behavioral insecticide resistance. Under this scenario, pests that can sense and avoid acquisition of lethal dosages of systemic insecticides within crop plants will have a selective advantage. This may lead to selection for insect behavioral avoidance, so that insects predominantly feed and oviposit on portions of crop plants with low concentration of systemic insecticide. Limited research has been published on the effect of environmental variables, including drought, on pesticide performance, but we present and discuss studies that support the hypothesis described above. In addition, we wish to highlight the importance of studying the many ways environmental factors can affect, directly and indirectly, both the performance of insecticides and the risk of target insect pests developing resistance.
authors.affiliation: Department of Entomology and Nematology, UC Davis Briggs Hall, Room 367, Davis, CA 95616 (haleh.khodaverdi@gmail.com; tmfowles.work@gmail.com; enbick@ucdavis.edu; chrnansen@ucdavis.edu) chrnansen@ucdavis.edu.
authors.forename: Haleh
authors.initials: H
authors.lastname: Khodaverdi
authors.affiliation: Department of Entomology and Nematology, UC Davis Briggs Hall, Room 367, Davis, CA 95616 (haleh.khodaverdi@gmail.com; tmfowles.work@gmail.com; enbick@ucdavis.edu; chrnansen@ucdavis.edu).
authors.forename: Trevor
authors.initials: T
authors.lastname: Fowles
authors.affiliation: Department of Entomology and Nematology, UC Davis Briggs Hall, Room 367, Davis, CA 95616 (haleh.khodaverdi@gmail.com; tmfowles.work@gmail.com; enbick@ucdavis.edu; chrnansen@ucdavis.edu).
authors.forename: Emily
authors.initials: E
authors.lastname: Bick
authors.affiliation: Department of Entomology and Nematology, UC Davis Briggs Hall, Room 367, Davis, CA 95616 (haleh.khodaverdi@gmail.com; tmfowles.work@gmail.com; enbick@ucdavis.edu; chrnansen@ucdavis.edu) State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, 198 Shiqiao Rd., Hangzhou 310021, China chrnansen@ucdavis.edu.
authors.forename: Christian
authors.initials: C
authors.lastname: Nansen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D005075:Biological Evolution; D057231:Climate Change; D018556:Crops, Agricultural / Q000502:physiology; D055864:Droughts; D007313:Insecta / Q000187:drug effects*; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*
chemical_list: D007306:Insecticides
keywords: IPM; behavioral insecticide resistance; climate change; neonicotinoid; systemic insecticide