亚洲玉米螟高致病力球孢白僵菌菌株的分离筛选

摘要

亚洲玉米螟Ostrinia furnacalis(Guenée)是我国玉米生产上的重要害虫,目前以化学防治为主.为寻求一种可持续的防治方法,本文从14株白僵菌菌株中初步筛选出对亚洲玉米螟致病力较强的6株白僵菌YB15、YB8、TB1126、TB1358、YB32、TB7,其致死中时间分别为0.66、1.44、1.29、0.99、1.42、1.28 d.同时测定了这6株白僵菌对亚洲玉米螟的致病力,从中筛选出产孢量大、萌发率高及毒力较强的球孢白僵菌YB15,在26℃条件下,该菌株浓度为1×109 孢子·mL-1时,亚洲玉米螟老熟幼虫死亡率达到96.67%,感染僵死率达到73.33%.在亚洲玉米螟的生物防治中有很好的应用潜力.%The Ostrinia furnacalis(Guenée)(Lepidoptera:Crambidae)is an important insect pest of corn in China.Chemical control is the usual treatment method at present.To explore strategies for sustainable control of the pest population,the pathogenicity of 14 isolates of the entomopathogenic fungus Beauveria bassiana to mature larvae of Asian corn borer was tested under laboratory conditions.Six strains(YB15,YB8,TB1126,TB1358,YB32 and TB7)were selected for their high virulence and the shorter half lethal time(LT50)on mature larvae of O.furnacalis as 0.66,1.44,1.29,0.99,1.42 and 1.28 days respectively.The virulence against the mature larvae of O.furnacalis was compared between the 6 strains,and the results showed that YB15 strain exhibited the highest germination rate and sporulation and the strongest virulence.It could cause the corrected mortality of 96.67% and the cadaver rate of 73.33% after inoculation with 1×109 spores per milliliter at 26℃for 10 days.In conclusion,the strain YB15 has high application value for biological control of O.furnacalis.