金龟子绿僵菌KMa0107菌株对三种玛绢金龟幼虫的致病力

Virulence of Metarihizum anisopliae Strain KMa0107 against Three White Grubs

室内测定了金龟子绿僵菌Metarhizium anisopliae菌株KMa0107对玛绢金龟属3种金龟子幼虫的致病力。结果表明,KMa0107菌株对玛绢金龟Maladerasp.、阔胫玛绢金龟M.verticalis和小阔胫玛绢金龟M.ovatula幼虫均具有较强的毒力。接种后,玛绢金龟、阔胫玛绢金龟、小阔胫玛绢金龟3种幼虫的毒力方程分别为Y=0.39X＋2.93（R2=0.97）、Y=0.41X＋2.33（R2=0.85）和Y=0.46X＋2.56（R2=0.97）。接种后3-9d,KMa0107菌株对玛绢金龟、阔胫玛绢金龟、小阔胫玛绢金龟幼虫的致死剂量对数值分别为9.09±0.3~5.26±0.18、9.04±0.29~4.67±0.21和7.35±0.18~4.7±0.17。在菌株KMa0107孢子悬浮液1.65×108~1.65×105孢子/ml浓度下,玛绢金龟、阔胫玛绢金龟和小阔胫码绢金龟幼虫LT50的估计值范围为3.4-6.2d、3.3-5.6d和2.7-4.7d。3种玛绢金龟幼虫接种绿僵菌孢子悬浮液后,随着病原菌的侵染,虫体血淋巴中蛋白质含量也随之发生变化。接种后4d,3种玛绢金龟幼虫血淋巴中蛋白质含量均明显下降。接种后2-6d,3种金龟幼虫血淋巴蛋白质含量减退率间差异显著,其中小阔胫玛绢金龟和阔胫玛绢金龟血淋巴蛋白质含量减退率明显高于玛绢金龟。

The virulence of the entomopathogenic fungus KMa0107,an isolate of Metarihizium anisopliae,against three white grubs,Maladera sp.,Maladera verticalis Fairmaire and Maladera ovatula（Fairmaire） was evaluated in laboratory.Results showed that the strain had a high virulence to the three species of white grubs,with a dose-effect parameter of 0.52,0.54 and 0.54 on larvae of Maladera sp.,M.verticalis and M.ovatula,respectively.A time-dose-mortality model was applied to analyze the mortality affected by both time and dose.The virulence equation was Y=0.39X＋2.93（R2=0.97）,Y=0.41X＋2.33（R2=0.85）,Y=0.46X＋2.56（R2=0.97） for the species of Maladera sp.,M.verticalis and M.ovatula, respectively. The lethal dosage caused by KMa0107 was significantly different for the tested three species of the grub chafers（F=10.50,P0.01）,and the lethal time was also significantly different（F=27.1,P0.05）.The logarithmic values of LC50 for Maladera sp.,M.verticalis,and M.ovatula were 9.09±0.3-5.26±0.18,9.04±0.29-4.67±0.21 and 7.35±0.18-4.7±0.17,respectively.The LT50 ranged 3.4-6.2 d,3.3-5.6 d and 2.1-4.7 d for Maladera sp.,M.verticalis and M.ovatula at the concentration of 105-107 conidia/ml,respectively.The content of the protein in the haemocytes decreased 4 d after inoculation,significantly lower than that in the control.The decrease rate of the protein content in the haemocytes in Maladera sp.,M.verticalis and M.ovatula was significantly different 2-6 d after the treatment, and the decrease rate was significantly higher in M.verticalis and M.ovatula than that in Maladera sp.