Study On The Level Of Cantharidin In Mylabris Cichorii Linnaeus And Artificial Rearing

Mylabris Cichorii Linnaeus(Coleoptera: Meloidae) is an important Chinese traditional medicine listed in the edited in 2005 (abbreviated as the Chinese Pharmacopoeia; Ch.P.) which potent content cantharidin is highly poisonous to most of animals. For its extensive using in medicine, the requirement has up increased and the natural resources of Mylabris Cichorii have been dramatically decreased in China. Therefore mass rearing of blister beetles will be the only way to solve the problem. But it seem very delicate and complex and now many efforts to set up the colony have failed.。In these few years, a series efficient research has been down by Chongqing University. This paper presents some the procedures of the insect mass rearing in laboratory and we cantharidin produced in different stages of M. cichorii rearing on this condition. The main results as follows:①The study on M. cichorii development on laboratory conditions was carried which showed that there are 5 instars in larval stage and the morphology and size showed great difference in each instar.②Photophase and temperature impacted M. cichorii development strongly on laboratory conditions. The lighting group of the larva (with a photoperiod of 14L:10D) was significantly superior to the darking group and for the adults eclosion also. It means a daily lighting is necessary for M. cichorii rearing. The experiment of the temperature optimize showed the optimum temperature for M. cichorii development is about 31℃. At these conditions, combine with the suit nutrition, M. cichorii will has no diapauses and can develop three generations under laboratory alternate one generation in the nature a year.③A new hemi-artifical medium was developed to release from the natural feed which can suffice development of the larvae first time. By this medium M. cichorii has been reared in our laboratory about 20 generations.④Two methods, by HCl and hot alkali extraction, of the cantharidin extraction were compared. The results showed that both methods have no considerable difference in reclaim ratio but hot alkali extraction is much convenient and lower polluted. Cantharidin crystal analyzed by thin layer chromatography and gas chromatography showed that the purity can reach to 99.5%.⑤The cantharidin levels in M. cichorii of different developing period were detected. The results indicated that the newly hatched larva have higher relative level of cantharidin but has very low absolute value because of the litter size. The cantharidin level was markedly increasing following the larvae's growing from the triungulin to the pupa. The separation rearing of the males and females showed that the adults are sexual dimorphism in cantharidin production. Adult beetles have very low cantharidin at the beginning after emergence, but the dose grows very fast after 5 days in male separated group, which will be at peak value in 30 days, at the same time in females group, the dose kept in low level in all lifetime. Otherwise, much higher cantharidin can be tested from female beetles in sex mixed rearing group after emergence for 20-30 days, but the level much lower in male beetles comparing to the separated rearing. This may indicate that a cantharidin transformation has occurred between males and females. The total amount of cantharidin biosynthesizes in mixed rearing group was much higher than the separated rearing group of M. cichorii adults. The highest cantharidin level presents in abdominal part of adults and lower level in thoracic part.