金腰箭提取物对菜粉蝶幼虫的拒食活性

测定了金腰箭不同提取物(甲醇、氯仿、石油醚)对菜粉蝶幼虫 的拒食活性，结果表明金腰箭甲醇提取物饲喂菜青虫的拒食活性最高，用1%浓度24 、48h(小时)的拒食率分别为92.2%与90.0%，同时测定了金腰箭 甲醇提取物对4、5龄菜粉蝶幼虫拒食中浓度AFC50和AFC90值，24h(小 时)分别为623.18、5277.59；1206.29、7923.24 μg·mL~(-1)， 48h(小时)分别为2454.99、106 51.89；2988.27、12584.31μg·mL~(-1)，进一步测定了其根 、茎、叶甲醇提取物对菜粉蝶幼虫的拒食活性，确定了活性物质最高部位为金腰箭叶，0.5 %叶甲醇提取物24、48h(小时)的拒食率分别为91.5%和85.0%， 其次为叶石油醚提取物，分别为73.7%和81.3%。

The Antifeedant Effectivity of Synedrella nodiflora against Pieris rapae

The Synedrella nodiflora extracts had high biology activity to Pieris rapae. Antifeedant efficiencies of 1% methanol e xtract were 92.22% and 90.0% at 24h and 48　h afte r feeding respectively. For the 4th instar larvae，AFC50 and AFC90 of the extracts were 623.18μg*mL-1，1　206.29μg*mL-1 at 24h，and were 2　454.99μg*mL-1 and 2　988.27　μg*mL-1 at 48h after feeding. For the 5th instar larvae，AFC50 and AFC90 were 5　277.59μg*mL-1 and 7　923.24μg*mL-1 at 24h ，and 10　651.89μg*mL-1 and 12　584.31μg*m L-1 at 48h feeding. The most effective constitute tested by bioass ay was the 0.5% extract of S.　nodiflora leaves with ethanol， antifeedant efficiencies were 91.5% and 85.0% at 24h and 48h. The second one was the leaves extract with petroleum ether，the an tifeedant efficiencies were 73.7% and 81.3% at 24h and 48h.