提升Bt和球孢白僵菌防治蛴螬效果的颗粒载体

为提升微生物杀虫剂对地下害虫蛴螬的防治效果，本研究研制了一种颗粒载体。首先，选择了生产企业常用的单螺杆膨化机作为生产设备，进一步通过颗粒大小、结构稳定性、生产过程等关键因素比较，确定了颗粒载体的物料配方（玉米粉、花生粕、膨润土比例为1：3：2，加水量20%）。进一步研究结果显示，Bt、球孢白僵菌等对蛴螬有效的杀虫微生物能够在颗粒载体上增殖生长。此外，本研究还发现对暗黑鳃金龟有效的Bt185与球孢白僵菌间无拮抗；暗黑鳃金龟幼虫的生物活性测定结果表明，颗粒载体与Bt185或球孢白僵菌结合后的校正死亡率为使用Bt185或球孢白僵菌单一粉剂的2倍，并且颗粒载体与这两种菌株协同使用的校正死亡率达77.55%，显著提升了Bt和球孢白僵菌单一粉剂对蛴螬的杀虫效果。上述研究结果为研制新型高效蛴螬生物杀虫剂提供了新思路，对突破目前蛴螬生物防治的瓶颈具有重要意义。

Study on the Granular Carrier to Enhance the Control Effect of Bacillus thuringiensis and Beauveria bassiana on Grubs

In order to improve the control effect of microbial insecticide against underground pest grubs,a granular carrier was developed.First of all,the single screw expander commonly used in the production enterprises was selected as the production equipment,and the material formula of the granular carriers(proportion of corn flour,peanut meal,bentonite was 1:3:2 and water content was 20%)was determined through the comparison of granular size,structural stability,production process and other key factors.Further research results showed that Bacillus thuringiensis(Bt)and Beauveria bassiana(Bb)and other insecticidal microorganisms that were effective against grubs could proliferate and grow on the granular carrier.In addition,this study also found no antagonism between Bt185 and Bb.Holotrichia parallela larvae biological activity test results showed that the corrected mortality of the combination of granular carrier with Bt185 and Bb was twice as high as that of single powder,and the corrected mortality of the combination of granular carrier with these two strains was 77.55%,which significantly improved the killing effect of single powder on grubs.Our results provided new ideas for the development of new high-efficient biological insecticides for grubs,which is of great significance to break through the current bottleneck of grubs biological control.