关键词: 棉蚜, 寄主植物, 杀虫剂, 抗性

Abstract: The susceptible strain and the resistant strains R-fenvalerate and R-imidacloprid of the cotton aphid (Aphis gossypii) were reared with three different host plants: cotton, cucumber and pomegranate. The toxicity of five insecticides to the decendants of the cotton aphid and the relevant enzymic activity were measured. The results showed that the resistance of the progeny of R-fenvalerate strain feeding on cotton was 67.4-folds higher than that feeding on cucumber for fenvalerate, and 0.5～4.6 folds for other four insecticides. When feeding on pomegranate this strain showed moderate resistance. The R-imidacloprid strain feeding on the three host plants showed the same tendency in resistance to the five insecticides as the R-fenvalerate strain. The sensitivity of the susceptible strain feeding on cucumber to the tested insecticides was higher than that feeding on cotton. AChE and CarE activities of different strains feeding on cotton were higher than feeding on cucumber (AChE:2.4～2.8 times;CarE:1.8～2.4 times). The results demonstrated that feeding on different host plants might cause the change in sensitivity to insecticides in the resistant and susceptible strains of the cotton aphid.  One of the major factor causing the resistance changes was the alteration in AChE and CarE activities.

Key words: Aphis gossypii, host plant, insecticide, resistance