绿僵菌对小菜蛾的感染反应分析

Analysis and Modeling of Time dose mortality of Metarhizium anisopliae Infecting Larvae of Plutella xylostella

用绿僵菌孢子悬浮液中浸渍过的甘蓝叶喂饲小菜蛾的方法 ,测定小菜蛾对 FI1 2 48菌株的感染反应。运用时间 -剂量 -死亡率模型 ,对死亡率随时间和剂量的变化作了拟合。接种后第9天的 L C5 0 为 4.1 7× 1 0 5～ 6 .33× 1 0 5孢子 / ml,在 1 0 7孢子 / ml浓度下的 L T5 0 为 4.7天。结果表明 FI1 2 48菌株对小菜蛾具有较强的致死作用。

WT4”BZ]Isolate FI1248 of Metarhizium anisopliae was bioassayed against larvae of Plutella xylostella. Larva was exposed to the cabbage leaf disc after immersed into conidial suspension. A time dose mortality model was applied to analyze the variation of mortality rates as affected by both time and dosage. The model showed considerable homogeneity in this isolate. Nine days after inoculation, the LC 50 was between 4.17×10 5～6.33×10 5 conidia/ml. With a dose of 10 7 conidia/ml concentration, the LT 50 was 4.7 days. The results showed that isolate FI1248 was highly virulent to P.xylostella.