Monitoring of resistance to several insecticides in brown planthopper (Nilaparvata lugens) in Huizhou.

The susceptibility of the brown planthopper(BPH),Nilaparvata lugens(Stl) to imidaeloprid,buprofezin,isoprocarb,butylene-fipronil,nitenpyram and chlorpyrifos,was monitored using the rice-stem dipping method in Huizhou,2009.The results indicate that local BPH populations have strong resistance to imidacloprid(resistance ratio of 422.2-fold),medium resistance to buprofezin and isoprocarb(resistance ratios of 11.0-14.0-fold,respectively),low resistance to butylene-fipronil(3.7-fold) and were still susceptible to nitenpyram and chlorpyrifos(resistance ratio 3-fold).The rational use of insecticides for N.lugens management is discussed in light of these results.