The Effect of Different Temperatures on Controlling Pine Caterpillars, Dendrolimus punctatus, by B.t Pesticide

Different temperatures affect the effect of controlling pine caterpillars, Dendrolimus punctatus, by B.t pesticide apparently.While using B.t pesticide,the mortality of D. punctatus decreased as the temperature dropped.From the result of 4 temperature gradient tests,it was showed that 20 ℃ is the threshold that determine the effect of controlling D. punctatus by B.t. The results shows that different temperatures affect the feeding deterrence of the B.t to the D. punctatus larvae also,but in the all temperature treatments,the feeding deterrences are apparent consistently.