木荷提取物对小菜蛾和菜青虫的拒食活性

室内测定了木荷甲醇提取物对小菜蛾、菜青虫3龄幼虫的拒食活性。结果表明，木荷树皮甲醇提取物对小菜蛾、菜青虫3龄幼虫的拒食活性最高。木荷树皮甲醇提取物在10g／L的质量浓度下，对小菜蛾3龄幼虫24h和48h的拒食率分别为94．27％和94．78％，拒食中浓度（AFC50）分别为2．7445g／L和1．5519g／L；对菜青虫3龄幼虫，在2g/L的质量浓度下，24h和148h的拒食率均达到100％，拒食中浓度（AFC50）分别为0．1053g／L和0．1488g／L。

Antifeedant Activities of the Extracts from Shima superba.et Champ.against Plutella xylostella and Pieries rapae

The antifeedant activities of the methanol extracts from Shima superba Gardn. et Champ. against 3rd instar Plutella xylostella L. and Pieries rapae L. were determined in laboratory. The results showed that the methanol extract from bark of Schima superba Gardn. et Champ. had the highest antifeedant activity. The 24 h and 48h antifeedant rates against 3rd instar Plutella xylostella L. were 94.27% and 94.78% when the concentration reached 10 g/L ,and 24 h and 48 h antifeedant median concentration(AFC50) was 2.7445 g/L and 1.5519 g/L. The 24 h and 48 h antifeedant rates against 3rd instar Pieries rapae L.were 100.00% when the concentration reached 2 g/L , and 24 h and 48h antifeedant median concentration(AFC50) was 0.1053 g/L and 0.1488 g/L .