median lethal time

The most virulent strain was screened out after evaluated by the indices of mortality, infection rate and the median lethal time ( LT50).

以桃蚜的校正死亡率、感染率及致死中时（LT（50））为指标综合评价不同菌株毒力。

The median lethal time ( LT50) of the GV was shortened with the increase of the virus concentration and the decrease of the larval instar, during which the GV was fed.

幼虫饲毒后，致死中时（LT（50））随病毒浓度提高而缩短；随饲毒时虫龄的增大而延长。

Median lethal time, mean lifespan and mean maximum lifespan of drosophila fed with different concentration of ponceau 4R were lower than those in control groups dominantly ( P < 0.05 or P < 0.01) in survival experiment, and a dose-response relationship was shown.

生存试验中各浓度组雌雄果蝇的半数死亡时间、平均寿命及平均最高寿命均较对照组缩短（P<0.05或P<0.01），且存在剂量-反应关系。

The median lethal time ( LT_ ( 50)) of P_ ( f) NPV to the larvae was shortened with the increase of the viral concentration.

各测试浓度下致死中时间（LT（50）为3.43-5.14天，随病毒浓度提高而缩短。