石斛象甲蜡蚧轮枝菌生物学特性·毒力及其可湿性粉剂的研究

目的]探讨石斛象甲蜡蚧轮枝菌的生物学特性及其毒力。方法]以从石斛象甲上分离出的蜡蚧轮枝菌为研究对象，研究温度对该菌菌落生长和菌落产孢量的影响以及该菌对烟蚜的毒力及其可湿性粉剂对烟蚜的毒力。结果]该菌菌丝生长和产孢的最适温度为30℃。该菌株对烟蚜有较高的毒力，随着浓度升高，杀虫效果明显增强，120h菌株的致死中浓度降到最低，为3．27×10^5孢子／ml。用固体培养法制成的粉剂悬浮率为74．65％，润湿时间为3．08min，在28℃培养48h可湿性粉剂的萌发率可达到85．8％。室内毒力测定表明该制剂对烟蚜具有较高的毒力。结论]该研究为进一步开发利用石斛象甲蜡蚧轮枝菌防治害虫提供了依据。

Study on Biological Characteristics Virulence and Wettable Powder of Verticillium lecanii from Weevil on Dendrobium nobil

Objective] The aim was to discuss the biological characteristics and virulence of Verticillium lecanii from weevil on Dendrobium nobil.Method] With V.lecanii separated from D.nobil weevil as research object,the effect of temperature on the colony growth and spore yield of the bacteria were studied,and the virulence of the bacteria and its wettable powder to Myzus persicae were studied.Result] The suitable temperature for mycelium growth and sporulation were 30 ℃.The strain had high toxicity to M.persicae and the insecticidal effect was increased obviously with the increment of concn.,and the LC50 of the strain reduced to minimum in 120 h,being 3.27×105 spore/ml.The suspensibility of wettable powder prepared by solid state fermentation process was 74.65%,wetting time was 3.08 min,germination rate of wettable powder cultured for 48 h in 28 ℃ reached 85.8%.The vtrulence indoor tests showed that the preparation had high toxicity to M.persicae.Conclusion] The research provided the basis for further development and application of V.lecanii from D.nobil weevil controlling pests.