应用球孢白僵菌防治北方越冬油松毛虫的研究

为在北方应用白僵菌防治油松毛虫,笔者采用从灵丘县干旱林区分离得到的油松毛虫病原球孢白僵菌菌株Beauveria bassiana CGMCC NO.1573制备的孢子悬浮液和营养型湿菌粉剂,分别在冬季和春季对越冬的油松毛虫幼虫进行防治。结果显示：用2×106个/mL孢子悬浮液的防治效果不好,校正死亡率只有21%～29%;冬季用菌粉防治效果较好,感染率达到70.4%～85.4%;春季施用菌粉15 d～20 d,感染率达47.1%～54.5%.结论认为,在树干基部和枯落物下撒施＂白僵菌营养型湿菌粉剂＂集中防治越冬幼虫是北方防治油松毛虫的有效方法。

Study on Application of Beauveria bassiana in Controlling Overwintering Dendrolimus tabulaeformis in North Forest

In order to control pine caterpillar effectively in north forest by using Beauveria bassiana,a strain of Beauveria bassiana CGMCC NO.1573,isolated from Dendrolimus tabulaeformis larva from droughty pine forest of Lingqiu County in Shanxi Province,used as spore suspension preparation and nutrition wet bacteria powder,was employed to the control tests in winter and springtime,respectively.The results showed that the control effect was poor by spraying suspension liquid containing spores of 2×106 numbers per mililiter,and the mortality of the Dendrolimus tabulaeformis larvae was only 21%-29%.While the control effect was very good by using the nutrition wet bacteria powder,the infection rate of overwintering larvae reached 70.4%-85.4%.By comparison,the infection rate reached 47.1%-54.5%,within 15-20 days after using the power preparation in spring.So the conclusion is that it is an effective method by broadcasting the nutrition wet bacteria powder preparation of Beauveria bassiana under the litter layer around the trunk base in the pine forest to control gregarious Dendrolimus tabulaeformis larvae in north China.