Resistance Monitoring of Field Populations of Panonychus citri to Three Pesticides

[Objectives]The paper was to investigate the development of Panonychus citri resistance to commonly used pesticides in major citrus producing areas in China,and to screen out new green and efficient agents for its control and prevention.[Methods]The resistance changes of field populations of P.citri to abamectin,pyridaben,and bifenazate in 12 locations across five provinces in China were compared using the leaf disc impregnation method.[Results]P.citri in the tested areas exhibited the most severe resistance to abamectin,with approximately 91.7%of the field populations showing high levels of resistance to abamectin(112.1-560.5 times);50%of P.citri populations exhibited high levels of resistance to pyridaben(123.0-202.7 times),while the remaining populations showed intermediate levels of resistance(25.6-80.3 times);except for the Zhejiang Xiangshan 2019 and Jiangxi Yudu 2019 populations,which exhibited a medium level of resistance to bifenazate,the remaining 10 monitored populations demonstrated a high level of resistance to bifenazate(140.4-686.1 times).[Conclusions]It is advisable to discontinue the use of abamectin and bifenazate due to significant resistance observed in populations of P.citri monitored in 12 locations across 5 provinces.It is recommended to reduce the frequency of pyridaben use and alternate with other acaricides that have different mechanisms of action due to the varying degrees of resistance developed.