用浸叶法测定了日本关西地区小菜蛾幼虫对乙酰甲胺磷、巴丹、氯氰菊酯和Ｂｔ４种不同类型农药的抗药性。试验明确小菜蛾在当地对上述４种参试农药都已产生不同程度抗药性。小菜蛾Ｒ系幼虫在２４０ｍｇ／ｋｇ氯氰菊酯、２００μｌ／ＬＢｔ浓度下死亡率分别仅为３７％、７２％。这两种农药目前已不能用于防治日本关西地区菜田小菜蛾 The resistance to Plutella xylostella larvae in the Kansai area of ​​Japan was tested for their resistance to four different types of pesticides, acephate, barden, cypermethrin and Bt, by dipping leaves. The test showed that the diamondback moth had produced different degrees of resistance to the above four types of pesticides in the locality. At the concentration of 240 mg / kg cypermethrin, the mortality of the R phase larvae of the diamondback moth was only 37% and 72% at the concentration of 200μl / LBt. These two kinds of pesticides can no longer be used to control the diamondback moth in Kansu region at present