| Rice stem-dipping method was used for determining the susceptibilities of white-backed planthopper to 8 insecticides, which collected from Guiyang, Pingba, Zunyi, Qianxi, Pingtang and Yuping rice production districts of Guizhou Province in 2013 and 2014.Results presented that different populations of Sogatella furcifera had the highest susceptibility to thiamethoxam, with LC50 value ranged from 0.060 to 0.93 mg/L and mean value of 0.33 mg/L. Followed by imidacloprid, chlorpyrifos, cycloxaprid and buprofezin, with LC50 values ranged from 0.080 to 2.84 mg/L, 1.09 to 3.89 mg/L, 0.59 to 10.07 mg/L and 0.28 to 18.15 mg/L, respectively, and with mean values of 1.03, 2.27, 2.71 mg/L and 4.96 mg/L, respectively. All S. furcifera populations showed much poor sensitivity to dichlorvos, pymetrozine and isoprocarb, with LC50 values ranged from 0.89 to 57.96 mg/L, and with mean LC50 values of 10.03, 12.16 and 22.44 mg/L, respectively. All six S. furcifera populations showed different sensitivities to the same insecticide. Resistance detection of six S. furcifera populations in Guizhou Province showed that the resistance levels of pymetrozine, buprofezin and imidacloprid were low to middle, while other five insecticides were all sensitive to S. furcifera. |
