Sensitivity of field populations of Grapholita molesta in Gansu Province to eight insecticides using the egg dipping method

Grapholita molesta (Busck) is an important pest in fruit tree production in northern China. In order to determine the resistance level of G. molesta population to commonly used insecticides in Gansu Province, the sensitivity of field populations of G. molesta from three different areas to eight insecticides was determined by the egg dipping method and the status of insecticide resistance was analyzed. The results showed that field populations of G. molesta showed moderate resistance to spinetoram (R_R = 10.24-14.27), low to moderate resistance to deltamethyrin (R_R = 8.85-11.44), moderate resistance to lambda-cyhalothrin, chlorantraniliprole and spirotetramat (R_R = 18.89-86.62), and high resistance to abamectin, emamectin benzoate and indoxacarb (R_R = 99.82-189.81). The results provide a scientific basis for the scientific and rational application of insecticides in the control of G. molesta in orchards.