用点滴法和浸叶法监测棉铃虫抗药性的比较

本文分别采用点滴法和浸叶法，监测了山东省阳谷县、河南省新乡县、河北省邯郸市和安徽省萧县第２代棉铃虫对氯氰菊酯、灭多威及久效磷的抗性，并对这两种方法的监测结果进行了比较。从同一种药剂对４个地区棉铃虫毒力大小顺序来看，两种方法的测定结果基本一致。而从抗性倍数来看，点滴法与浸叶法的结果具有差异：点滴法测得的氯氰菊酯的抗性倍数（２０．８～３４．８倍）高于浸叶法测得的抗性倍数（２．０～１８．７倍），对灭多威测得的抗性倍数（５．４～１６．４倍）也高于浸叶法测得的抗性倍数（１．４～６．５倍）；而浸叶法测得的对久效磷的抗性倍数（１１．３～７０．１倍）却明显高于点滴法测得的抗性倍数（２．８～９．３倍）。本文并对产生这种差异的原因进行了分析和讨论，建议对有机磷杀虫剂采用浸叶法作抗性监测比较确。

Evaluation of Two Resistance Monitoring Methods in Helicoverpa armigera: Topical Application Method and Leaf Dipping Method.

Resistance to cypermethrin, methomyl and monocrotophos in Helicoverpa armigera collected from four provinces of China (Shandong, Hebei, Henan and Anhui) was monitored by both topical application method and leaf dipping method (IRAC Method No. 7) in 1995. A susceptible strain of H. armigera collected from Yanshi county, Henan Province had been reared under insecticide free conditions since 1991. Resistance ratios to cypermethrin (20.8 34.8 fold) by topical application method were higher than that (2.0 18.7 fold) by leaf dipping method. Resistance ratios to methomyl (5.4 16.4 fold) by topical application method were also higher than that (1.4 6.5 fold) by leaf dipping method. However, resistance ratios to monocrotophos (2.8 9.3 fold) by topical application method were lower than that (11.3 70.1 fold) by leaf dipping method. The reasons causing such difference in two resistance monitoring methods were discussed. It is suggested that it is more sensitive to monitor organophosphate insecticides resistance in H. armigera by leaf dipping method.