杠柳根皮乙醇粗提液对菜青虫的拒食作用及其防治效果

测定了杠柳 (PeriplocasepiumBunge .)其根皮乙醇粗提液对菜青虫Pierisrapae (L .)的拒食活性 ,并进行了乙醇粗取液及其与氯氰菊酯混用防治菜青虫药效试验。生测结果表明 ,乙醇粗提液对菜青虫 4龄和 5龄幼虫具有较强的拒食活性 ,2 4h拒食中浓度分别为 1 3 2 0 8mg L和 1 1 96 3mg L ,且对拒食后试虫生长发育有严重的影响。药效试验结果显示 ,乙醇粗提液 1 0 0倍液及其混配制剂 1 0 0 0倍液对菜青虫具有较好的防治效果。温室处理后 5d ,杠柳乙醇粗提液 1 0 0倍液、混剂 1 0 0 0倍液的防虫效果与 1 0 %氯氰菊酯 1 0 0 0倍液效果相当 ;田间处理后 5d ,杠柳粗提液防虫效果虽然较差 ,但保叶效果仍达 60 %以上 ,而混剂的防虫和保叶效果均与氯氰菊酯效果相当。

Antifeedant effect and control efficacy of ethanol crude extracts from the root bark of Periploca sepium against imported cabbage worm,pieris rapae

The result of bioassay indicated that the ethanol crude extract from Periploca sepium Bunge had strong antifeedant effect on Pieris rapae 4 and 5-instar larvae, and the AFC 50s at 24 h were 1 320.8 mg/L and 1 196.3 mg/L respectively. The experiment also indicated that the extract had obvious effects on protecting leaves and some control effect on the pest. Results in green house showed that the extract with dilution of 100 times and the mixture of ethanol extracts and cypermethrin with dilution of 1 000 times gave the same pest control effect as cypermethrin with dilution of 1 000 times giving in 5 days after treatment. Field trials showed that the extract with 100 times gave better effect for leave protection although the extract gave lower effect for pest control, but the efficacy of the mixture with dilution of 1 000 times both on leaf protection and on pest control was similar to 10% cypermethrin EC with dilution 1 000 times.