雷公藤总生物碱对几种昆虫的生物活性

为进一步确定雷公藤总生物碱的杀虫作用谱和作用方式,评价其应用前景,采用室内生测法研究了对小菜蛾、菜青虫、棉铃虫、黏虫、玉米象、桃蚜、山楂叶螨、家蝇的生物活性。结果表明,雷公藤总生物碱对小菜蛾3龄幼虫、黏虫3龄幼虫、菜青虫5龄幼虫、桃蚜无翅成蚜、山楂叶螨雌成螨和棉铃虫3龄幼虫48 h的毒杀活性LC50分别为228.28、306.39、307.61、0、435.90、622.17、653.00 mg/L,72 h后LC50分别为136.67、216.12、238.18、309.67、485.36、463.00 mg/L;对家蝇成虫也有较好的毒杀作用;对棉铃虫幼虫生长有明显抑制作用;对玉米象有较强的种群抑制作用。

Bioactivity of the total alkaloid from Tripterygium wilfordii Hook against several important pests

The bioactive spectra and action modes of the total alkaloid from Tripterygium wilfordii Hook to Plutella xylostella(L.),Pieris rapae,Helicoverpa armigera(Hübner),Mythimna separata Walker,Sitophilus zeamais(Motschulsky),Myzus persicae(Sulzer),Tetranychus viennensis Zacher and Musca domestica L.were investigated.The results showed that its LC50 values to the 3rd instar larvae of P.xylostella after treatment for 48 h and 72 h were 228.28 mg/L and 136.67 mg/L,respectively,while those to the 3rd instar larvae of M.separata were 306.39 mg/L and 216.12 mg/L,respectively and 653 mg/kg and 463 mg/kg to the 3rd instar larvae of H.armigera.Its LC50 values to the 5th instar larvae of P.rapae were 307.61 mg/L and 238.18 mg/L,respectively,435.90 mg/L and 309.67 mg/L to the wingless adults of M.persicae,and 622.17 mg/L and 485.36 mg/L to the female adults of T.viennensis,respectively.The total alkaloid was also toxic to M.domestica adults.The alkaloid imposed a great influence on the growth of H.armigera after 3th instars fed by the foods treated with the alkaloid.The larvae had a acute reduction in body weight,compared with the control.The alkaloid also had a strong inhibitory effect on the population size of S.zeamais.The alkaloid was more toxic to many pests and had more modes of action.It is therefore promising in IPM.