Rapid development of resistance in Myzus persicae Sulz. to cypermethrin

Detection of development of resistance in Myzus persicae Sulz. to phosphamidon, and synthetic pyrethroid cypermethrin was studied in the laboratory. Response of the population of M. persicae to insecticides showed LC₅₀ values of cypermethrin and phosphamidon as 0.024 and 0.056%, respectively. A comparison of LC₅₀ values obtained during 1988 and 1992 revealed that M. persicae had developed 5-fold resistance to cypermethrin. However, the aphid pest showed only 1.8-fold resistance to phosphamidon. This suggests that the development of resistance to cypermethrin was rather faster as compared to phosphamidon.