白僵菌与绿僵菌对甜菜夜蛾幼虫的致病力

The virulence of Beauveria bassiana and Metarhizium anisopliae strains against Spodoptera exigua larvae

分别测定了4株球孢白僵菌和5株金龟子绿僵菌菌株对甜菜夜蛾幼虫的致病力.结果表明:以(1.0±0.5)×108个·mL-1的孢子悬液接菌8 d后,白僵菌B187和绿僵菌Ma1291-2菌株对该幼虫有较强的致病力,其校正死亡率分别为(93.21±3.20)%和(94.70±0.68)%,僵虫率分别为(84.76±1.47)%和(88.06±1.75)%,致死中时(LT50)分别为5.57和5.33 d.通过时间—剂量—死亡率模型参数估算,2株菌对该幼虫致死效应较强的时间段在接种后4-5 d.2株菌对该虫6 d的致死中浓度(LC50)分别为6.41×106和8.49×105个·mL-1.这说明2株菌有较大的开发应用潜力.

4 strains of Beauveria bassiara （Bals.） Vuill and 5 strains of Metarhizium anisopliae （Metsch.） Sorokin were tested for pathogenicity to Spodoptera exigua （Hübner） larvae.The results indicated that the strains B187 and Ma1291-2 possessed a stronger virulence to S.exigua larvae inoculated with （1.0 ±0.5） × 10^8 conidia · mL-1 for 8 days.The correct mortality and cadaver rate of B187 treating were （93.21 ±3.20）% and （84.76 ± 1.47）%,and those of Ma1291-2 were just （94.70 ±0.68）% and （88.06 ± 1.75）% respectively.For the two strains,the half lethal times （LT50） were 5.57 d and 5.33 d respectively.A time-dose-mortality model was employed to estimate parameters of time and dose,which showed that the time with a stronger lethal effect of the two strains on S.exigua larvae was 4-5 days after inoculation.The half lethal concentrations （LC50） of the two strains to larvae on the 6th day were 6.41 × 10^6 conidia · mL-1 and 8.49 × 10^5 conidia · mL-1 respectively.It suggested that the two strains had important application potential.