球孢白僵菌对东亚飞蝗和梨冠网蝽侵染的温湿度效应  

Effects of Humidity and Temperature on the Pathogenecity of Beauveria bassiana against Stephanitis nashi and Locusta migratoria manilensis

作　　者：白云[1] 崔雨虹[1] 曹娜[1] 刘义豪[1] GHULAM Ali Bugti 王滨[1] 

机构地区：[1]安徽农业大学微生物防治省重点实验室,合肥230036

出　　处：《中国生物防治学报》2016年第6期735-742,共8页Chinese Journal of Biological Control

基　　金：国家自然科学基金(31471822);安徽省年度重点项目(1301043049)

摘　　要：环境的温湿度变化对昆虫病原真菌侵染害虫造成直接的影响。本文研究了在不同温湿度变化下,球孢白僵菌Bb2352对梨网蝽和东亚飞蝗侵染率的变化动态与趋势。结果表明,在1.0×107孢子/m L悬浮液接种、25℃饲养条件下,2种不同昆虫的死亡率均随着湿度的增加而增加。经检验湿度效应对死亡率的数量影响吻合时间-剂量-死亡率模型(TDM模型),拟合得到的新的时间-湿度-死亡率(THM)模型能准确地描述球孢白僵菌Bb2352侵染的湿度效应。THM模型显示,当相对湿度达到85%以上时,梨冠网蝽的死亡率增速明显快于蝗虫;梨冠网蝽死亡率随湿度变化的时间效应参数γ在第8 d(γ8)达到最大,而东亚飞蝗死亡率随湿度变化的时间效应参数γ在第11 d(γ11)达到最大,显示出球孢白僵菌Bb2352侵染不同昆虫的湿度效应有所差异。在温度效应研究中,当环境相对湿度>95%时,菌株Bb2352侵染2种目标昆虫的累计死亡率均在25℃达到最大,增加或降低温度均会降低菌株Bb2352的侵染效率。Logistic模型拟合显示该模型能准确反映球孢白僵菌Bb2352侵染目标害虫的温度效应。本文中湿度THM模型和温度Logistic模型的构建是数学描述昆虫病原真菌对害虫侵染温湿度效应的有益尝试。Temperature and relative humidity pose great effects on the virulence of entomopathogenic fungi. The objective of this study was to examine the effect of interacting conditions of temperature and relative humidity on fungal infection of Beauveria bassiana towards Stephanitis nashi and Locusta migratoria manilensis. The insects were inoculated with conidia suspension of B. bassiana at a concentration of 1.0×107 spores/m L and were fed and held at 25 ℃. It was observed that the fungal virulence increased with the increase of relative humidity. To describe mortality dynamic of the tested insects, a model of time-humidity-mortality（THM）, derived from the model of the time-dose-mortality（TDM）, was established. Development of the fungal disease could be well described by the THM model with the change of humidity and time variables. The THM model showed that, when humidity was over 85%, the mortality of S. nashi was significantly higher than that of L. migratoria manilensis. By comparison of the mortalities in different days, the time parameters γ maximized on the 8th day for S. nashi and on the 11 th day for L. migratoria manilensis, indicating that S. nashi is more sensitive to the change of relative humidity than L. migratoria manilensis. As to temperature effects, when relative humidity was over 95%, the fungal infection on both the tested insects peaked at 25 ℃. Temperature effects on the insects＇ mortality could not be described by the TDM model but could be fitted well with a logistic model. The model results indicate that S. nashi is easier to be infected than L. migratoria manilensis as evidenced by a faster infection speed and a shorter infection period. The construction of the THM and logistic models is a good way to understand the effects of relative humidity and temperature on fungal infection towards different target insects.

关 键 词：梨网蝽 东亚飞蝗 球孢白僵菌 THM模型 逻辑斯蒂方程 

分 类 号：S476.12[农业科学—农业昆虫与害虫防治]