Sublethal effects of sulfoxaflor on the fitness of two species of wheat aphids, Sitobion avenae (F.) and Rhopalosiphum padi (L.)

Sitobion avenae (F.) and Rhopalosiphum padi (L.) are two important pests of wheat in China. They typically coexist in fields during the late period of wheat growth. Sulfoxaflor is a novel sulfoximine insecticide that demonstrates broad-spectrum efficacy, especially in targeting sap-feeding insects. This study was carried out to investigate the sublethal effects of sulfoxaflor on the development, longevity, and reproduction of two species of wheat aphids. Our results showed that sublethal concentrations of sulfoxaflor did not cause significant effects on the fecundity or the longevity of the parent generation (F0 generation) of either S. avenae or R. padi. However, it caused transgenerational sublethal effects. For S. avenae , adult longevity of F1 generation was significantly decreased. No significant differences were observed on the population parameters of S. avenae in the F1 generation. For R. padi, the adult preoviposition period (APOP) and the total preoviposition period (TPOP) of F1 generation were significantly reduced. The mean generation time (T) was significantly reduced in the R. padi F1 generation. What’s more, the intrinsic rate of increase (rm) and the finite rate of increase (λ) were significantly increased in the R. padi F1 generation. Taken together, these results suggest that exposure to the LC25 of sulfoxafl had no effects on the parent generation of S. avenae or R. padi, but it reduced adult longevity of S. avenae as a negative effect and increased the r m and λ of R. padi in the first progeny generation, which may have an impact on the population dynamics of R. padi.