球孢白僵菌与印楝素复配对草地螟的增效作用

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

测定了不同配比的球孢白僵菌(Beauveria bassiana)菌株S3与印楝素对草地螟(Loxostege stfcticalis L.)幼虫致病率的增效作用。通过数学模型对复配剂的共毒系数与复配剂中单剂的比例关系进行拟合,获得了最佳理论配比。测试结果表明,白僵菌菌株与印楝素在1:10、1:4、1:2、1:1和5:2配比作用下对草地螟幼虫都有增效作片用,7×10~7孢子/mL白僵菌菌株S3与14 mg/mI。印楝素的最佳理论配比为3 978:l,此时混剂对草地螟幼虫具有最大的共毒系数333.608 3。田间试验亦证明混用能提高药效,具有较显著的增效作用。

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.