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为确定苍耳Xanthium sibiricum对昆虫活性最高的部位,测试了苍耳不同器官(果实、叶、茎和根)甲醇提取物对几种重要十字花科蔬菜害虫(包括小菜蛾Plutella xylostella,菜青虫Pieris rapae,桃蚜Myzus persicae和萝卜蚜Lipaphis erysimi)的拒食活性、产卵忌避活性或忌避活性.结果表明,苍耳的主要活性部位为地上部分,尤其是叶和果实,其次是茎,根的活性最低.拒食活性测试中,苍耳叶提取物对菜青虫最强,在所测试的浓度下,处理后24 h的选择性拒食率高达99.07%;对小菜蛾幼虫的拒食作用以果实和叶提取物最强,选择性拒食率分别高达82.87%和73.42%.产卵忌避/忌避活性最强的是苍耳叶提取物,处理后24 h对小菜蛾成虫的选择性产卵忌避率达88.57%,对萝卜蚜和桃蚜的选择性忌避率分别为83.01%和62.50%,同时,苍耳果实提取物对小菜蛾、桃蚜和萝卜蚜的产卵忌避/忌避活性明显高于茎和根提取物.基于苍耳叶和果实提取韧对害虫强烈的拒食、产卵忌避或忌避活性,有可能作为植物保护剂配方应用于害虫的综合治理策略中.“,”Antifeedant, and oviposition or inhabiting ( settling) deterrent effects of methanol extracts from the fruit, leaf, stem and root of Xanthium sibiricum is investigated in a laboratory setting using different bioassays, aim at determining which part extracts is more effective on the four key insect pests of crucifers, including Plutella xylostella, Pieris rapae, Myzus persicae and Lipaphis erysimi. Antifeedant effects are examined in the larva of P. xylostella and P. rapae, using leaf disc choice bioassays, in addition to oviposition deterrent effects of adult P. xylostella using a fresh leaf disc choice bioassay, and inhabiting deterrent effects of L. erysimi and M. persicae using half-leaf choice bioassays. The results show that the leaf extracts show the highest antifeedant rate overall for P. rapae, with the most effective antifeedant rate of 99.07% , and fruit extracts prove the highest antifeedant rate for P. xylostella with a rate of 82. 87% , while the most effective oviposition deterrent rate, derived from leaf extracts, is a deterrent rate of 88.57% for P. xylostella. The most effective inhabiting deterrent rate is also recorded from leaf extracts for L. erysimi, 83. 01% and 62. 50% for M. persicae. Extracts from X. sibiricum fruit presented a more potent oviposition and inhabiting deterrent for the three insects, than did either stem or root extracts. Based on their antifeedant, and oviposition deterrent and inhabiting deterrent properties, the active components from X. sibiricum show the potential to be used as alternative crop protectant against a number of pest species.