关键词: 德国小蠊, 抗药性, 消退

Abstract: Objective To learn the resistance fadeaway of Blattella germanica in passenger trains to dichlovos(DDV) and trichlorphon after organophosphates prohibition for two years. Methods The resistance was assayed by the jam bottle method advocated by WHO. Results Before fadeaway, the knock-down times (KT₅₀) of DDV and trichlorphon were 64.78 and 57.45 min, respectively. The resistance ratio of DDV and trichlorphon were 20.37 and 15.48, respectively. After fadeaway, the KT₅₀ of DDV and trichlorphon to B.germanica captured from the field decreased to 15.62 and 12.45 min, respectively. The resistance ratio decreased to 4.91 and 3.35, respectively. The KT₅₀ of DDV and trichlorphon to laboratory B.germanica strain were 11.75 and 10.28 min, respectively. The resistance ratio was 2.59 and 2.75, respectively. Conclusion The resistance of B.germanica in passenger train to insecticides can decrease after conventional breeding in the laboratory or organophosphate prohibition for 2 years.