Abstract: This study aims to detect imidacloprid residue in wheat seeds harvested form seeds treated with different dosages of imidacloprid and its impact on the development and reproduction of the grain aphid, Sitobion avenae (Fabricius). Wheat seeds were coated with imidacloprid (60% FS) in a proportion of 2, 4, 6, and 8 g/kg, respectively, and imidacloprid residue in harvested wheat seeds was detected by UPLC-MS/MS. Life table of S. avenae laboratory populations was constructed to compare various parameters of this insect feeding on wheat plants grown from the harvested seeds. The results showed that imidacloprid residue was positively correlated with the treatment dosage, and the residue in wheat seeds harvested form seeds treated with 8 g/kg imidacloprid reached the highest level (0.0290 mg/kg). Life table metrics showed that the larval and imaginal periods were shortened, and the proportion of alates and aphid fecundity were increased in the treatments, but no significant difference existed in these parameters between the treatments and the control (P=0.392＞0.05). Net reproduction rate, the intrinsic rate of increase and the finite rate of increase in the treatments were, respectively, higher than those of the control. In addition, the population doubling time and the mean generation time in the treatments were reduced compared to the control. But there were no significant differences in all of the parameters between the treatments and the control (P=0.406). The results suggest that trace residue of imidacloprid in wheat seeds has no significant impact on the development of S. avenae, but affects the reproductive capacity of aphids in certain degree.

Key words: Sitobion avenae, imidacloprid, seed dressing, residue, developmental duration, fecundity, life table parameters