人工饲养条件下眼斑芫菁不同发育阶段斑蝥素含量的变化

【目的】分析人工饲养条件下眼斑芫菁Mylabris cichorii Linnaeus不同发育阶段体内斑蝥素含量的变化。【方法】收集不同发育阶段的眼斑芫菁，通过热碱浸提法提取斑蝥素，而后以气相色谱法检测含量。【结果】在幼虫期，1龄幼虫斑蝥素相对含量最高，2龄幼虫斑蝥素相对含量降到最低点；以后随着虫体的发育，幼虫体重和斑蝥素含量都逐渐增加。羽化后的成虫经隔离饲养，雄虫在羽化后5～30天大量合成斑蝥素，而雌虫体内斑蝥素含量则极低，具有典型的性二型现象；雌雄混合饲养组中，20～30天雌虫体内可以检测到大量斑蝥素，而同期雄虫斑蝥素含量远低于隔离饲养组。【结论】幼虫期斑蝥素含量随虫体发育而增加；成虫期主要由雄虫合成斑蝥素。混合饲养组成虫平均单头斑蝥素含量高于隔离饲养组雌雄虫平均斑蝥素含量。成虫身体各部位的斑蝥素含量以腹部最高，胸部次之。

Changes of cantharidin content in Mylabris cichorii Linnaeus (Coleoptera: Meloidae) at different developmental stages under laboratory conditions

Objective] To analyze changes on the level of cantharidin at different life stages in telini fly Mylabris cichorii Linnaeus artificially reared under laboratory conditions.Methods] Cantharidin was extracted respectively from different life stages and different parts of adult body of the beetle by hot alkali extraction and detected with gas chromatogram.Results] During the first five instars,larvae accumulated cantharidin as they grew and developed.Adult beetles kept sex-segregated exhibited a pronounced sexual dimorphism in cantharidin biosynthesis.The male produced a great deal of toxin in 5-30 days after emergence,while in the female very low level of cantharidin was detected.Much higher canthardin level,however,was detected from female beetle in sex-mixed rearing group in 25 days after emergence.Conclusion]Larvae accumulate cantharidin as they grow and develop.Adult beetles exhibit a pronounced sexual dimorphism in cantharidin biosynthesis,but total content of cantharidin produced by sex-mixed rearing group is much higher than that by sex-segregated rearing group.The highest cantharidin level presents in abdominal part of adults and lower level in thoracic part.