球孢白僵菌不同分离株对西花蓟马的毒力测定

【背景】西花蓟马是我国重要的一种入侵性害虫,已对多种化学农药产生了抗性。【方法】采用孢子悬浮液喷雾处理生测法,研究了8个球孢白僵菌菌株BbKM030716、BbCG051229、BbJS080625、BbQJ031121、BbXW060615、BbSM090521、BbYY090613和BbMZ051230对西花蓟马成虫的毒力,并用＂时间—剂量—死亡率＂模型进行了分析。【结果】供试球孢白僵菌各菌株对西花蓟马成虫侵染致病的剂量效应参数值分别为1.43、0.87、0.93、0.98、1.23、0.92、1.07和0.86。用1.25×104～1.25×108个·mL-1孢子悬浮液接种后,连续10d内西花蓟马的校正死亡率分别为44.13%～98.49%、12.63%～78.90%、30.36%～96.92%、51.36%～98.74%、26.14%～98.59%、7.27%～78.71%、49.06%～98.74%和27.67%～87.36%。球孢白僵菌对西花蓟马成虫的致死剂量是时间的函数,各菌株对西花蓟马成虫的致死中时随孢子浓度的增大而逐渐减小。【结论与意义】球孢白僵菌菌株BbKM030716、BbJS080625、BbQJ031121和BbXW060615对西花蓟马成虫具有较强毒力,可作为西花蓟马生防制剂开发的潜力菌株。

Virulence of isolates of the insect pathogen Beauveria bassiana against the Western flower thirps,Frankliniella occidentals

[Background]The western flower thrips,Frankliniella occidentals（Pergande）,is one of the invasive insect pests in China,and is resistant to many insecticides.In order to develop alternative methdos of control,we tested the virulence of eight isolates,of the insect pathogen Beauveria bassiana namely,BbKM030716,BbCG051229,BbJS080625,BbQJ031121,BbXW060615,BbSM090521,BbYY090613 and BbMZ051230 to F.occidentals was assessed in the laboratory.[Method]Virulence was characterised by a standard time-dose-mortality model.[Result]The lethal concentration LC50 values vaired with time after inoculation and the lethal dose LT50 values varied with concentration.The virulence index for different isolates of B.bassiana against western flower thrips was 1.43,0.87,0.93,0.98,1.23,0.92,1.07 and 0.86 respectively.The corrected mortality incresed from 44.13% to 98.49%,12.63% to 78.90%,30.36% to 96.92%,51.36% to 98.74%,26.14% to 98.59%,7.27% to 78.71%,49.06% to 98.74%,and 27.67 to 87.36%,by inoculation of the dose of 1.25×104～1.25×108 conidia·mL-1 over 10 consecutive days.The mortality of adult thrips was dose and time-dependent.Value of LT50 was decreased with the increase of the concentration.[Conclusion and significance]The isolates of BbKM030716,BbJS080625,BbQJ031121 and BbXW060615 were the most virulent isolates against F.occidentalis and show promsie as biological control agents.