Abstract: 【Aim】 The objective of this study is to assess the resistance of Myzus persicae populations to conventional insecticides in tobacco production areas in Guizhou province, southwestern China. 【Methods】 Resistance of M. persicae field populations collected from 34 major tobacco production counties and cities of nine districts in Guizhou to acetamiprid, deltamethrin and pirimicarb was assayed with dipping method. 【Results】 The results of the resistance monitoring of 34 M. persicae populations to three insecticides indicated that the two populations collected from Qianxinan (Xingyi) and Bijie (Qianxi) maintained sensitivitydecreasing level to acetamiprid (RR=4.00-4.31), while other 32 populations developed moderate level resistance to acetamiprid (RR=10.09-26.35). For deltamethrin, the Bijie (Bijie) and Qiandongnan (Tianzhu) populations developed moderate level resistance (RR=32.47-38.72). The Bijie (Qianxi), Tongren (Sinan) and Anshun (Anshun) populations developed extremely high level resistance (RR=184.97-237.77). The other populations developed high level resistance to deltamethrin (RR=51.27-132.08). For pirimicarb, the populations collected from Bijie (Bijie), Qiandongnan (Shibing and Tianzhu) and Zunyi (Yuqing) developed low level resistance (RR=5.90-9.46), while the other populations developed moderate level resistance (RR=10.05-31.66). 【Conclusion】 The results suggest that most field populations of M. persicae in Guizhou have developed low to extremely high level resistance to the insecticides, which may be due to the wide use of these insecticides in tobacco production areas. The results provide important guidance for the choice and wise application of insecticides in the control of Myzus persicae in fields in tobacco production areas of Guizhou.

Key words: Myzus persicae, insecticide, insecticide resistance, tobacco production areas, Guizhou