Abstract: 【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.

Key words: Mylabris cichorii, cantharidin, sexual dimorphism, artificial rearing