Sublethal Dose of -Cypermethrin Impairs the Olfaction of by Suppressing the Expression of Chemosensory Genes.

The oriental fruit fly, , is one of the most destructive fruit insect pests. -cypermethrin has been widely used in the orchard to control this major insect. Based on the resistance monitoring in 2011, developed significant resistance against -cypermethrin in fields. This indicated that the has been exposed to sublethal concentrations of -cypermethrin in the field for a long time. Thus, it is urgent to understand the sublethal effects of -cypermethrin on this fly to guide the rational use of an insecticide. According to the olfactory preference assays and electroantennogram (EAG) recording, the after -cypermethrin exposure (LD = 10 ng/fly) severely decreased the ability to perceive the tested odorants. Moreover, we then performed quantitative real-time PCR and found the chemosensory genes including odorant receptor co-receptor () and ionotropic receptor co-receptors (BdorIRcos) were obviously suppressed. Our results demonstrated that the sublethal dose of -cypermethrin impairs the olfaction of the pest insects by suppressing the expression of chemosensory genes ( and BdorIRcos), which expanded our knowledge of the sublethal effects of the pesticide on insects.