水菖蒲两种提取方法粗提物对谷蠹和玉米象的触杀活性

CONTACT TOXICITY OF EXTRACTS OBTAINED BY TWO ESTRACTION METHODS FROM ACORUS CALAMUS L. RHIZOME AGAINST RHYZOPERTHA DOMINICA(F.) AND SITOPHILUS ZEAMAIS(M.)

为进一步开发利用植物源杀虫剂,实现安全和绿色储粮,分别以甲醇冷浸法、超临界CO2萃取法(SFE-CO2)对水菖蒲Acorus calamusL.根茎中的生物活性物质进行提取,采用药膜法研究了水菖蒲提取物对谷蠹Rhyzopertha dominica Fabricius、玉米象Sitophilus zeamais Motschulsky成虫的触杀活性。结果表明:甲醇冷浸法、SFE-CO2对水菖蒲根茎的提取率分别为9.44%和5.51%。水菖蒲两种方法提取物对谷蠹、玉米象成虫均具较强触杀活性,并且对谷蠹成虫的触杀活性均明显强于其对玉米象成虫的触杀活性,其中,甲醇冷浸提取物比SFE-CO2提取物对谷蠹、玉米象成虫具有更强的触杀活性。对谷蠹成虫,甲醇冷浸提取物、SFE-CO2提取物处理4 d后的LD50分别为22.98μg/cm2和33.94μg/cm2;对玉米象成虫,其相应的LD50分别为159.89μg/cm2和394.35μg/cm2。

To further exploit botanical insecticides for safe and green grain storage, the methods of methanol soa- king and supercritical fluid CO2 extraction （SFE--CO2） were adopted respectively to extract some bioactive substance from Acorus Calamus L. rhizome, the contact toxicity of extracts against adults of Rhyzopertha dominica Fabricius and Sitophilus zeamais Motschulsky were studied with the residual film method in this paper. The results showed that the extraction rates of Acorus calamus L. rhizome by methanol soaking method and SFE--CO2 method were 9.44% and 5.51%, respectively. Extracts all had good contact toxici- ty against adults of R. dominica and S. zeamais, meanwhile they all acted more effectively on adults of R. dominica than adults of S. zeamais, and extract obtained by methanol soaking method had more effective action against adults of R. dominica and S. zeamais than extract obtained by SFE--CO2 method. After exposing for 4 days to extract obtained by methanol soaking method and SFE--CO2 method the LD50 were 22.98 and 33.94μg/cm^2 respectively for R. dominica adults, while the LD50 for S. zeamais adults were 159.89 and 394.35μg/cm^2 respectively.