Phenotypic analysis of dinotefuran resistance in the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae), using the experimental evolution approach

Abstract

Insecticide applications for controlling insect pests drive the rapid phenotypic evolution of resistance traits within populations. In two decades, the brown planthopper, Nilaparvata lugens, has rapidly developed resistance to imidacloprid, a neonicotinoid insecticide, but its resistance to dinotefuran has not developed as quickly. We assume that the genetic mechanism underlying the resistance evolution of N. lugens differs between the imidacloprid- and dinotefuran-resistant phenotypes. Dinotefuran-resistant strains, collected from a paddy field in Kumamoto in 2013 (Res-D13) and 2014 (Res-D14), were subjected to quantitative genetic analysis. The realized heritabilities of dinotefuran resistance were 0.091 (Res-D13) and 0.084 (Res-D14) after the 15th generation of selection. Reciprocal cross experiments between Res-D13 and the susceptible strain (Sus-strain), and between Res-D14 and the Sus-strain, showed that the degree of dominance for dinotefuran resistance ranged from 0.34 to 0.57. Analysis of the F₂ population and backcrosses to the parental strains indicated that dinotefuran resistance is a quantitative trait controlled by multiple genes on autosomal chromosomes. We propose that the realized heritability and the mode of inheritance of dinotefuran resistance well explain the slow development of dinotefuran resistance in field N. lugens populations.