Abstract: 【Aim】 In order to ascertain the resistance status of Frankliniella intonsa to six commonly used insecticides (imidacloprid, thiamethoxam, sulfoxaflor, afidopyropen, flupyradifurone and cyantraniliprole) in major cotton growing areas of Xinjiang, Northwest China. 【Methods】F. intonsa provided by Yunnan Agricultural University was used as the susceptible strain. The median lethal concentration (LC₅₀) values of the above six insecticides against the adults of the field populations of F. intonsa from Awati County of Aksu, Zepu County of Kashgar, Heshlik Township of Korla and Manas County of Changji were determined by dipping method. The resistance levels of the four populations to the six insecticides were evaluated based on the LC₅₀ value. 【Results】 In addition to remaining sensitive to cyantraniliprole, the four field populations of F. intonsa in Xinjiang developed different degrees of resistance to the other five insecticides. Among them, Korla population had the highest level of resistance to imidacloprid, reaching the moderate resistance level, and the resistance ratio (RR) was 32.6. The Zepu population had the highest resistance level to flupyradifurone, showing a medium resistance level, and the RR was 15.7. The resistance levels of the four field populations of F. intonsa to thiamethoxam, sulfoxaflor and afidopyropen were low and moderate (5.0<RR≤40.0). 【Conclusion】 Cyantraniliprole can be used as a recommended insecticide to control F. intonsa in the field, and suggested to be alternately used with other insecticides with different mechanisms of action to delay the development of insecticide resistance in F. intonsa.

Key words: Frankliniella intonsa, cotton, insecticides, resistance monitoring