Insecticidal activities of the non-allkaloid extracts from Tripterygium wilfordii against Plutella xylostella
雷公藤非生物碱对小菜蛾的生物活性研究

The tests on insecticidal activities of the non-alkaloid extracts from Tripterygium wilfordii Hook.f.against Plutella xylostella L.were conducted.The results show that the non-alkaloid extracts from T.wilfordii has a strong antifeedance toxicity and growth inhibiting activities.The medium antifeedance concentration(AFC_ 50)of the non-alkaloid extracts against the 2 nd instar larva of P.xylosella are 34.89mg/L and 42.33mg/L in the choice and no-choice tests,respectively.The medium lethal concentration(LC_ 50)against the 2 nd instar of P.xylosella is 49.86mg/L.The non-alkaloid extracts also shows a strong growth inhibiting activity to the larva of P.xylosella.But the effect of the non-alkaloid extracts on the eggs of L.xylosella is not obvious.The egg hatchability and survival rate of the newly-hatched larva of P.xylosella treated with 400mg/L of the non-alkaloid extracts are 53.48% and 46%,respectively.