旅客列车德国小蠊抗药性消退研究

目的了解旅客列车德国小蠊在停止使用有机磷类杀虫剂2年后，对敌敌畏、敌百虫的抗性消退情况。方法按照全国爱卫办统一规定的果酱瓶药膜法测定杀虫剂的抗性。结果在抗性消退前，敌敌畏的KT50为64．78min，抗性系数为20．37；敌百虫的KT50为57．45min，抗性系数为15．48。抗性消退后，现场品系德国小蠊对敌敌畏的KT50为15．62min，抗性系数为4．91；敌百虫的KT50为12．45min，抗性系数为3．35。抗性消退后实验室品系德国小蠊对敌敌畏的KT50为11．75min，抗性系数为2．59；敌百虫的KT50为10．28min，抗性系数为2．75。结论旅客列车德国小蠊经实验室正常饲养或停止使用有机磷类杀虫剂2年后，抗性可以明显消退。

Study on resistant fadeaway of the Blattella germanica in passenger trains

Objective To learn the resistance fadeaway of Blattella germanica in passenger trains to dichlovos（DDV） and trichlorphon after organopbosphates prohibition for two years. Methods The resistance was assayed by the jam bottle method advocated by WHO. Results Before fadeaway, the knock-down times （KTs0） of DDV and tfichlorphon were 64.78 and 57.45 rain, 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 rain, respectively. The resistance ratio decreased to 4.9l and 3.35, respectively. The KT50 of DDV and trichlorphon to laboratory B.germanica strain were 11.75 and 10.28 rain, 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.