Sublethal effects of sulfoxaflor on biological characteristics and vitellogenin gene (AlVg) expression in the mirid bug, Apolygus lucorum (Meyer-Dur)

The mirid bug, Apolygus lucorum (Meyer-Dur) has evolved the resistance towards some traditional insecticides, especially pyrethroids and organophosphates. Sulfoxaflor, as a novel insecticide, is used for control of sap feeding insects, like A. lucorum. Therefore, it is necessary to determine the acute toxicity and the potential sublethal effects of sulfoxaflor in A. lucorum. Here, the LD50 value of sulfoxaflor against A. lucorum was assayed as 3.347 ng/adult at 48 h via topical application. Besides, the effects of a sublethal dose (LD15) of sulfoxaflor on biological characteristics of A. lucorum were estimated by comparison of the life table parameters. The long-evities and fecundity of parent generation did not exhibited significant difference between both control and treatment groups after exposure to LD15 dose of sulfoxaflor (0.568 ng/adult) for 48-h. However, the parameters reflecting their progeny G1 generation population dynamics, including the intrinsic rate of increase (ri), the finite rate of increase (lambda), the mean generation time (T), the net reproductive rate (R-0) and gross reproduction rate (GRR) significantly reduced in the treatment group compared to the control. Furthermore, the expression level of AlVg mRNA significantly decreased by 43.8% in the progeny whose parents were treated with LD15 dose of sulfoxaflor in comparison with the control transgenerational female adults. These results suggested that sublethal dose of sulfoxaflor adversely affect the development and reproduction of transgenerational A. lucorum. The downregulation of AlVg might have negative impacts on the fecundity of A. lucorum.