Synergistic Activity of Combination of Azadirachtin and Beauveria bassiana on Loxostege sticticalis L.

In this paper,the synergistic effect of Beauveria bassiana strains S3 and Azadirachtin at different ratio against Loxostege stiaicalis L.was evaluated by calculating co-toxicity coetticient(CTC).The optimal ratio was attained by using Excel、DPS data software on the basis of bioassay,the mathematical model,and by fiting mixtures co-toxicity coefficient and the ratio of the single dose.The results showed that,the synergism between Beauveria bassiana strain and Azadirachtin at the ratio of 1:10,1:4,1:2,1:1,5:2 had be showed.When the best theory ratio of 7×10~7 spores/mL Beauveria bassiana strain S3 and 14 mg/mL of Azadirachtin is 3 978:1,the mixture have the greatest co-toxicity coefficient 333.608 3.