中文摘要：

大螟（Sesamia inferens Walker）是危害甘蔗的重要害虫,防治困难,为了寻找对该虫的生物防治措施,本研究采用浸渍法生物测定了球孢白僵菌Bb10716菌株在15～30℃下对该虫三龄幼虫的致病性.结果表明,在15,18,21,24,27,30℃下,接种Bb10716菌株1.21×103 ～ 1.21×108孢子/mL孢子悬浮液后第10天时大螟幼虫的校正死亡率分别为（10.00±2.32）％～（56.67 ±3.45）％,（16.67±2.76）％～（76.67±2.65）％,（23.33±2.58）％～ （90.00±3.45）％,（33.33±2.25）％～ （98.55±3.35）％,（36.67±3.65）％～（98.65±3.33）％,（46.67±3.25）％～（98.98±4.34）％.在15,18,21,24,27,30℃条件下,菌株Bb10716对大螟三龄幼虫的毒力回归方程分别是y=2.68＋0.33X（R2=0.92）,Y=3.00＋0.34X（R2=0.91）,Y=3.14＋0.38X（R2=0.89）,Y=2.79＋0.52X （R2 =0.91）,Y=2.917＋0.55X（R2 =0.91）,Y=3.321 ＋0.58X（R2 =0.89）;致死中浓度LC50分别是9.37×106,6.85×105,8.05×104,9.89×103,3.87×103,1.39×103孢子/mL.在15,18,21,24,27,30℃条件下用1.21×108孢子/mL孢子悬浮液接种后,对大螟三龄幼虫的致死中时LT50分别为（6.9±1.8）,（5.6±0.5）,（5.0±0.6）,（4.9±0.3）,（4.4±0.5）,（4.2±0.4）d.综合测定结果,球孢白僵菌Bb10716菌株对甘蔗上大螟幼虫具有较强的致病性,可作为甘蔗上大螟幼虫生物制剂开发用菌株.

英文摘要：

The pink stem borer,Sesamia inferens Walker is an important pest insect on sugarcane,and it is difficult to control.To get a strategy for the biocontrol on the pink stem borer,the Pathogenicity of the isolate Bb10716 of Beauveria bassiana against the 3rd larvae of S.inferens was tested under temperature ranged from 15 to 30℃.Results showed that the corrected mortality of S.inferens on 10th day was （10.00±2.32）% ～ （56.67 ±3.45）%,（16.67 ±2.76）% ～ （76.67 ±2.65）%,（23.33±2.58）% ～ （90.00 ±3.45）%,（33.33 ±2.25）% ～ （98.55 ±3.35）%,（36.67± 3.65） % ～ （98.65 ± 3.33） %,（46.67 ± 3.25） % ～ （98.98 ± 4.34） %,after the inoculation of the conidia concentration of 1.21 × 10^3 ～ 1.21 × 10^8 conidia/mL under the temperature of 15,18,21,24,27 and 30℃,respectively.The virulence regression equation was Y =2.68 ＋ 0.33X （R2 =0.92）,Y=3.00 ＋0.34X （R2 =0.91）,Y=3.14 ＋0.38X （R2 =0.89）,Y=2.79 ＋0.52X （R2 =0.91）,Y=2.917 ＋0.55X （R2 =0.91） and Y=3.321 ＋0.58X （R2 =0.89） under the temperature of 30,27,24,21,18,15,respectively.The LC50 value was 9.37 × 10^6,6.85 × 10^5,8.05 × 10^4,9.89 × 10^3,3.87 × 10^3,1.39 × 10^3 conidia/mL under the temperature of 15,18,21,24,27,30℃,respectively.TheLT50was （6.1 ±0.32）,（5.2±0.28）,（5.6±0.38）,（6.3±0.35）,（6.59±0.39）,（8.85±1.23）,（9.35 ± 1.25） d by inoculation of 1.21 × 10^8 condia/mL B.bassiana concentration.All above results showed that isolate Bb10716 of B.bassiana was virulent against the 3rd larvae of S.inferens and it can be a potential strain for the development of biological control agent against the S.inferens.