The growth and development effects of twelve Chinese medicines on the larvae of cotton bollworm

In order to control the damage of Helicoverpa armigera effectively,the high active and environmental-friendly plant insecticide was screened and researched.The growth and development effects of twelve Chinese medicines,including Brucea javanica,Brassica alba and Nerium indicum etc,on the larvae of Helicoverpa armigera were tested by diet-incorporated method in this article.The result showed that,ten Chinese medicines has inhibited their weight growth,The larvae weight inhibiting rate were 17.25%-102.19%,Brycea javanicaNerium indicumScutellaria barbataMelia azedarachBrassica albaRheum palmatumHerbal andrographisUlms macrocarpaToona sinensisFolium isatidis.After treated with Brucea javanica,the larvae period delayed for 7.31 day,the emergence rate decreased 64.47%.After treated with Brassica alba,it had significant effect on pupating rate and pupal weight.The pupal weight inhibiting rate was 73.31%.The Brassica alba and Brucea javanica were higher in activity on the larvae of cotton bollworm in the twelve Chinese medicines and the value of further research was needed.