球孢白僵菌和金龟子绿僵菌对红火蚁工蚁的致病力测定

Pathogenicity of Beauveria bassiana and Metarhizium anisopliae to Solenopsis invicta workers

为了评价白僵菌和绿僵菌对红火蚁的致病力,寻找其生物防治菌株资源,采用浸液法测定了11株球孢白僵菌(Beauveria bassiana Balsamo)和9株金龟子绿僵菌(Metarhizium anisopliae Metschnikoff)菌株对红火蚁工蚁的致病力。结果表明:以浓度1×10^7个孢子·mL-1接菌红火蚁工蚁,10 d后,白僵菌和绿僵菌对其校正死亡率范围分别为(6.47±0.98)%^(67.14±0.22)%和(35.13±1.25)%^(81.93±0.94)%;白僵菌BSX-PC和绿僵菌MaWys-01菌株对红火蚁的致病力较强,致死速度较快,致死中时(LT50)分别为(5.64±0.52)d和(4.78±0.46)d。测定不同浓度对红火蚁的致病力,白僵菌BSX-PC和绿僵菌MaWys-01菌株以浓度1×10^8个孢子·mL^-1接菌后10 d,其校正死亡率分别为(79.59±0.5)%和(99.20±0.80)%,僵虫率为(63.24±0.51)%和(81.92±1.39)%,两菌株对红火蚁6 d的致死中浓度(LC50)分别为1.01×10^6和2.42×10^5个孢子·mL^-1。通过时间-剂量-死亡率模型分析,两个菌株致死效应最强的时间均是接菌后3~5 d。综合分析,白僵菌BSX-PC和绿僵菌MaWys-01菌株在红火蚁生物防治中有较大应用潜力。

To evaluate the pathogenicity ofBeauveria bassiana(Balsamo)andMetarhizium anisopliae(Metschnikoff)toSolenopsis invicta(Buren),the pathogenicity of various biological control strains was investigated.In this study,the pathogenicity of 11 B.bassianastrains and 9 M.anisopliaestrains toS.invictawas determined by the soaking method.The results showed that the corrected mortality rate ofB.bassianastrains andM.anisopliaestrains to worker ants ofS.invictavaried from(6.47±0.98)%-(67.14±0.22)% and(35.13±1.25)%-(81.93±0.94)%,respectively,after inoculation with a concentration of 1×10^7 spores·mL^-1 for 10 d.Among all strains tested,BSX-PC and MaWys-01 exhibited the strongest pathogenicity toS.invicta;the median lethal time(LT50)was shorter with(5.64±0.52)d and(4.78±0.46)d,respectively.When inoculated with a concentration of 1×10^8 spores·mL^-1 for 10 d,the corrected mortality rates of BSX-PC and MaWys-01 toS.invictawere(79.59±0.50)% and(99.20±0.80)% and cadaver rates were(63.24±0.51)% and(81.92±1.39)%,respectively.The median lethal concentration(LC50)of BSX-PC and MaWys-01 to worker ants for 6 d was 1.01×10^6 and 2.42×10^5 spore·mL^-1,respectively.Analysis of a time-dose-mortality model showed that the most lethal effects of BSX-PC and MaWys-01 toS.invictawere 3-5 d after inoculation.Collectively,the data suggest that these two strains have considerable potential for application in the biological control ofS.invicta.