Control Effects of Three Biological Pesticides against Dendrolimus punetatus

[Objective] The aim was to explore control effects of three biological pesticides against Dendrolimus punetatus to provide reference for effectively prevent and inhibit the damage of D.punetatus.[Method] The laboratory toxicity was tested on the 5th instar larvae of D.punctatus with Bacillus thuringiensis(Bt),Avermectins and Aacillus thruringlensis-Abamectin and Bt(0.3% Lindebao) by topical application method,and the forest control effect of 0.3% Lindebao against D.punetatus was studied.[Result] The laboratory toxicity LC50 value of Lindebao was only 18.25 mg/L.Lindebao raw dust and light calcium carbonate mixed in the proportions of 1∶10,1∶15,1∶20 and 1∶25 in weight had effective forest control effect on D.punetatus,with the control effects of over 80%,among them the proportions of 1∶10 and 1∶15 had the best control effect.[Conclusion] The proportion of 1∶15 of Lindebao power has effective and economic control effect on the 5th instar larvae of the first generation of D.punctatus,so it is suitable for preventing and controlling D.punctatus within the vast area of forest.