2株生防菌与苏云金杆菌混配对茶园扁刺蛾的防治效果研究

Control Effect of Two Strains of Biocontrol Bacteria Mixed with Bacillus thuringiensis on Thosea sinensis in Tea Garden

为优选到一个对茶园扁刺蛾高防效的生防菌混配配方来替代化学药剂防治扁刺蛾,采用生防菌两两混配的方法,将前期从茶园发现的自然死亡扁刺蛾尸虫肠道内筛选到的2株生防菌(X-2、X-11)分别与苏云金杆菌(Bt)混配。室内毒力试验表明,筛选到的X-2和X-11生防菌与Bt制剂间具有协同增效作用,可以提高对扁刺蛾的防效,其中尤以1×10^(8)个/mL X-11+32 IU/mg Bt混配菌剂对扁刺蛾的防治效果最好,其药后72 h的死亡率最高可达81.50%,较单独施用1×10^(8)个/mL X-11菌液的死亡率提高了22.9个百分点。田间试验表明,将优选到的混配菌剂在茶园喷施10 d后对扁刺蛾的防效最高可达67.20%,比对照Bt菌剂防效提高了8.8个百分点。该研究可为今后茶园扁刺蛾生物防治制剂的开发利用提供理论基础。

To select a biocontrol bacterial mixture formula with high control effect on Thosea sinensis Walker to replace chemical pesticides,the study used a method of pairwise mixing of biocontrol bacteria.Two strains of biocontrol bacteria(X-2,X-11)selected from the gut of the naturally dead Thosea sinensis Walker found in tea gardens were mixed with Bacillus thuringiensis(Bt).Indoor toxicity tests showed that the X-2 and X-11 biocontrol bacteria had a synergistic effect with Bt,which can improve the control effect on the Thosea sinensis Walker.Especially,the mixed microbial agent made by mixing 1×10^(8)/mL of X-11 bacterial solution and 32 IU/mg of Bt had the best control effect on Thosea sinensis Walker,with a maximum mortality rate of 81.50%after 72 hours,which was 22.9 percent points higher than that of the X-11.Field experiments showed that after spraying the mixed microbial agents selected in tea gardens for 10 days,the highest control effect on the Thosea sinensis Walker could reach 67.20%,which was 8.8 percent points higher than that of the Bt.This study can provide a theoretical basis for the development and utilization of biological control agents against Thosea sinensis Walker in the future.