球孢白僵菌和金龟子绿僵菌对红火蚁工蚁的致病力测定

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。

Pathogenicity of Beauveria bassiana and Metarhizium anisopliae to Solenopsis invicta workers

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.