竹提取物对棉铃虫幼虫及菜青虫的拒食活性

研究结果表明 ,质量浓度为 1 0g L的 1 0种供试竹提取物对棉Helicoverpaarmigera铃虫均具有较强的拒食作用 ,1 2h拒食率最高达 95 . 0 3 % ,最低为 74. 0 7% ,其中毛金竹 (Phyllostachysnigravar.henonis)、白纹短穗竹 (Brachystachyumalbostriatum)提取物对棉铃虫 3龄幼虫的AFC50 (拒食中浓度 )分别为 2 . 0g L、2. 7g L ,但 2 4h、48h拒食率均明显下降。对菜青虫 3龄pierisrapae幼虫的拒食效果以凤凰竹 (Bambusamultiplex)提取物最好 ,2 4h拒食率为 71. 69% ;对 4龄菜青虫的拒食效果以毛金竹提取物最好 ,拒食率为71 . 45 % ,其中毛金竹、白纹短穗竹 2种竹提取物对菜青虫 3龄幼虫的AFC50 分别为 2 .68g L和 3 . 3 7g L。研究结果对于开发环境友好农药以及充分利用竹类资源均具有重要意义。

Antifeedant activity of the extracts from bamboo against Helicoverpa armigera and Pieris rapae

The antifeedant activity of the extracts from 10 bamboo species against Helicoverpa armigera and Pieris rapae is reported. The results showed that the extracts of the bamboo at their dose of 10 g/L showed fairly good antifeedant activity to H. armigera. After 12 h, the antifeedant rate was from 95.03% to 74.07%. The antifeedant median concentration (AFC_(50)) of the extracts of Phyllostachys nigra var. henonis and Brachystachyum albostriatum against 3rd-instar larvae of H. armigera was 2.00 g/L and 2.07 g/L respectively. However, the rates descended significantly after 24 h and 48 h. The antifeedant activity of the extract from Bambusa multip lex against 3rd-instar larvae of P. rapae was the best, the antifeedant rate of which was the highest(71.60%) after 24 h. The extracts of P. nigra var. henonis and B. albostriatum showed fairly good antifeedant activity against the 3rd and 4th instar larvae of P. rapae, their AFC_(50) were 2.68 g/L and 3.37 g/L, 2.04 g/L and 2.67 g/L respectively.