Assessment of the effects of lethal and sublethal exposure to dinotefuran on the wheat aphid Rhopalosiphum padi (Linnaeus).

The wheat aphid Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae) is a devastating pest of wheat crops worldwide. Dinotefuran, a novel neonicotinoid insecticide, has been used to prevent piercing-sucking agricultural insects, such as R. padi. This research showed that the dinotefuran not only caused direct mortality but also affected the physiology of R. padi via sublethal effects. In this study, residual film bioassay results indicated that there were no significant differences in the toxicity of dinotefuran between field in 2017 and laboratory strains. However, the longevity, fecundity and female preoviposition of the F0 generation were significantly decreased by exposure to different sublethal doses (L10, L20 and L30) of dinotefuran. In contrast, the fecundity and female preoviposition of the F1 generation were significantly increased by the sublethal treatment L20, although this dose reduced net reproductive rate, intrinsic rate of increase and finite rate of increase. These findings are the first laboratory evidence of hormesis attributable to low dinotefuran doses. Developmental duration of nymphs was significantly increased by the sublethal doses L20 and L30 but not L10. Sublethal exposure to dinotefuran can increase the transgenerational population growth of R. padi and affected demographic parameters of the target insect. This study provides useful data for developing management strategies for R. padi involving the use of dinotefuran.