【目的】 筛选斑蝥素衍生物，寻找高效、低毒、低残留的新型化合物研发杀虫剂。【方法】 采用生物测定和酶活性测定方法，对100种斑蝥素类衍生物进行筛选，采用叶碟饲喂法测定其对粘虫3龄幼虫的胃毒活性；测定亚致死剂量下试虫体内解毒酶系的活性变化。【结果】 通过生物测定发现斑蝥素衍生物Ⅰ-7^#和Ⅳ-13^#的杀虫活性优于去甲斑蝥素，Ⅰ-7^#与斑蝥素对粘虫的胃毒LC₅₀值相近，其LC₅₀分别为49.818 mg/mL和43.677 mg/mL。酶活性测定结果表明：斑蝥素、斑蝥素衍生物去甲斑蝥素、Ⅰ-7^#和Ⅳ-13^#对粘虫解毒酶系酶比活力均有不同程度的影响，其中对细胞色素P450酶比活力有明显的抑制活性，对羧酸酯酶比活力有不同程度的激活作用，而对谷胱甘肽S-转移酶比活力大体表现出先激活后抑制的活性。【结论】 斑蝥素衍生物Ⅰ-7^#和Ⅳ-13^#对鳞翅目害虫有较强杀虫活性,具有作为生物源农药加以开发利用的价值。

 [Objectives]  Screening from cantharidin derivatives to find high efficient, low toxic and residual chemicals for R&D of new pesticides. [Methods]  Using bioassay and enzymatic determination methods to test 100 cantharidin derivatives. Stomach poison activity to the 3^rd-instar larvae of Mythimna separata was tested by using leaf disc feeding method and their activity of the detoxification enzyme system was determined by sublethal dose. [Results]  Bioassay results suggested that the effects of the derivatives Ⅰ-7^# and Ⅳ-13^# were better than norcantharidin; the stomach poison LC₅₀ of Ⅰ-7^# was similar to cantharidin and their LC₅₀ were 49.818 and 43.677,mg/mL respectively. The results of enzyme activity assay elucidated that cantharidin and its derivatives norcantharidin, Ⅰ-7^# and Ⅳ-13^# influenced detoxifying enzyme system of M. separata in different degrees. Among them, the specific activity of cytochrome P450 (P450) significantly reduced while carboxylesterase (CarE) is activated in different degrees by the cantharidin derivatives, and the specific activity of glutathione S-transferase (GST) generally showed activation at first and then inhibition. [Conclusion]  Cantharidin derivativesⅠ-7^# andⅣ-13^# have strong insecticidal activity against lepidopteran pests and are of value for development and utilization as biopesticides.