胡芦巴不同溶剂粗提物对主要储粮害虫的生物活性研究

THE BIOACTIVITIES OF DIFFERENT EXTRACTS FROM TRIGONELLA FOENUM-GRAECUM AGAINST IMPORTANT STORED-GRAIN INSECT

本研究采取回流提取法,以豆科植物胡芦巴为材料,选用无水乙醇、氯仿、乙酸乙酯、丙酮、石油醚5种溶剂进行粗提。并以主要的储粮害虫玉米象、锯谷盗为试验对象,对粗提物的触杀、驱避作用进行了测定。结果表明:5种溶剂对胡芦巴的提取率为乙醇>乙酸乙酯>氯仿>丙酮>石油醚。各粗提物对2种储粮害虫表现出较强的触杀作用。胡芦巴的乙醇粗提物(上层)及乙酸乙酯粗提物对玉米象的触杀活性最强,处理48h后的LD50分别为0.328mg/cm2、0.334mg/cm2。触杀活性最低的是石油醚粗提物,处理72h后的LD50为0.582mg/cm2。对锯谷盗而言,乙醇(上层)、乙酸乙酯、石油醚、氯仿4种溶剂粗提物的触杀作用均比丙酮粗提物的强。所有粗提物对2种储粮害虫也都表现出一定的驱避作用,玉米象与锯谷盗的驱避率之间差异不显著。

The powderded seeds of Trigonella foenum--graecum were extracted with ethanol, chloroform, ethylacetate, acetone and petroleumether at relative high temperature by dipping the extract in flask with warm water. And five different extracts were tested for their insecticidal activities against Sitophilus zearnais （Motschulsky） and Oryzaephilus surinamensis （Linnaeus） using repellence method and contact toxicity. The results showed that the extraction rate of Trigonella foenum--graecum seeds was ethanol〉ethylacetate〉chloroform〉acetone〉petroleumether. All the extracts had good contact poison action on two insects. The ethanol extracts （superstratum） and ethylacetate extracts had the most effective contact toxicity to S. zeamais, and the values of LD50 were 0. 328 mg/cm2 and 0. 334 mg/cm2 after 48h treatment. The petroleumether extracts had the lowest contact toxicity, and the values of LD50 was 0. 582 mg/cm2 after 72h treatment. As far as O. surinamensis was concerned, the extracts obtained by ethanol（superstratum）, ethylacetate, petroleumether and chloroform had better contact poison action than acetone extract. All the different extracts had repellence action on two insects to some extent, and the difference of repellency rates between S. zeamais and O. surinamensis did not cause obviously by Trigonella foenum--graecure extracts.