北京地区中国梨木虱的抗药性评价及不同药剂对其田间防效OA

The relative sensitivity baseline of Cacopsylla chinensis to imidacloprid 97%,beta-cypermethrin 99.9%,spirotetramat 97.8%,flonicamid 97.96%,and abamectin 93.3%were established by dipping method.The resistance levels of four field populations of C.chinensis to insecticides in Beijing region were evaluated,and the field efficacy trials of five commercially available insecticide mixtures were carried out in Daxing district.The results showed that the LC50 values of flonicamid,spirotetramat,imidacloprid,abamectin,beta-cypermethrin to the sensitive population of C.chinensis were 7.87,7.62,1.83,0.57,4.19 mg/L,respectively.C.chinensis in Beijing region exhibited moderate to low resistance to beta-cypermethrin and abamectin(with resistance ratios of 7.35-14.30,6.96-10.84,respectively),reduced susceptibility to moderate resistance to spirotetramat and imidacloprid(with resistance ratios of 3.48-11.22 and 3.84-12.85,respectively),and remained sensitive to flonicamid(with resistance ratio of 1.09-1.31).After 15 days of field application,the control effect of spirotetramat·dinotefuran 20%suspension concentrate(SC)with 2 000-fold dilution reached 100%,and the control effects of abamectin·spirotetramat 25%SC with 4 000-fold dilution and flonicamid·spirotetramat 30%SC with 5 000-fold dilution were 99.73%and 98.66%,respectively.Spirotetramat was still a key effective pesticide for the control of C.chinensis,but resistance management measures should be taken to delay the development of resistance according to the medium resistance level and the decreasing trend of sensitivity.