Effects of multigenerational imidacloprid stress on sensitivity to imidacloprid of Schizaphis graminum(Rondani)
In order to explore the resistance risk and biochemical mechanism of Schizaphis graminum(Rondani)to insecticides,the tolerance level and response of esterase activities to the imidacloprid were assessed after multiple generations of S.graminum have been exposed to the imidacloprid stress.After continuous stress with imidacloprid for ten generations,the sensitivity of S.graminum to imidacloprid significantly decreases with a 5.29-fold of LC50 value higher than that of the control population.Analysis of variance displays that there is no significant difference for the esterase activity between the control and continuous stressing populations by imidacloprid for ten genera-tions.However,the soluble protein contents of stressing populations increase significantly compared with that of the control.Tolerance to imidacloprid of LC50 values for different treatment aphid populations is significantly and posi-tively correlated with their protein contents.The tolerance level of S.graminum populations to imidacloprid increases after continuous stress with LC50 dosage.Esterase activity has no significant response to imidacloprid stress,but it could induce a significant increase of their soluble protein contents.The results suggest that populations of S.grami-num could have a certain risk of developing resistance to imidacloprid.Therefore,it is necessary to scientifically ar-range the use interval,alternate or rotate the use of pesticides,and then avoids or delay the development and pro-gression of insecticide resistance in the field.
万方数据
维普
