Studies On The Activity Effect And Mechanism For Bioactive Compound From Stellera Chamaejasme L. Against Larvae Of Pieris Rapae L.

The toxin 1,5-diphenyl-3-hydroxyl-1-pentanone, a high, active compound isolated from the extract of the roots of Steliera chamaejasme, was tested for the bio-activity effect on the larvae of Pieris rapae. So as to prove up the mechanism, the larvae's content of the hepatin and the blood lymph was determined, and the change of the larvae's inner organs was observed through dissection and micro-slice-up.The leaf-dipped method, injection method, stomach method and larvae-dipped method were adopted to mesure the toxicity. The result showed that the toxin has good toxicity. And the toxicity through injection was better than others, the effect by tomach method was not so remarkable. The toxicity became weak if the instar of larvae were old. To the same instar larvae, The toxicity of longer effect time was stronger than the shorter one. The non-choice leaf-dipped method, choice leaf-dipped method and drop method were adopted to mesure antifeedant effect.The result showed that the toxin has good antifeedant activity. The antifeedant effect became weak if the instar of larvae were old. And the antifeedant effect of older larvae was weaker than that of the younger ones.The result of biochemistry tests showed that the toxin was able to restrain the...