Selection for imidacloprid resistance and mode of inheritance in the brown planthopper, Nilaparvata lugens

BACKGROUND Strong resistance to imidacloprid in Nilaparvata lugens (Stål) has developed in Southeast and East Asia. Although the mode of inheritance for resistance is very useful information for pest control, this information is unknown in N. lugens. Here, we established two resistant strains that were selected from field populations in Vietnam and the Philippines, and conducted crossing experiments to determine the inheritance pattern. RESULTS The resistance ratio of 50% lethal dose (LD50) values for the two resistance‐selected strains, i.e., resistant strains originating from Vietnam (VT‐Res) and the Philippines (PH‐Res), to their control strains were ∼ 8‐ and 157‐fold, respectively. Reciprocal cross experiments between VT‐Res and the susceptible strain (S‐strain), and between PH‐Res and the S‐strain showed that the degree of dominance was 0.81 and 0.82, and 0.95 and 0.96, respectively. Analysis of the F2 populations and backcrosses to the parental strains indicated that resistance is a major‐gene trait following Mendelian inheritance. The strength of the resistance was suppressed by pre‐treatment with piperonyl butoxide, an inhibitor of cytochrome P450‐monooxygenases. CONCLUSION Our results suggest that imidacloprid resistance in N. lugens is autosomal and an almost completely dominant major‐gene trait that is likely manifested by high expression levels of a detoxification enzyme. © 2019 Society of Chemical Industry Using crossing experiments between resistant and susceptible strains, imidacloprid resistance in the brown planthopper was determined to be autosomal, almost completely dominant and a major‐gene trait.