摘 要 ：在恒温条件下 ,研究了甜菜夜蛾 3龄初幼虫感染核型多角体病毒后的病死速率、病死时间分布与温度关系。结果表明 ,在2 9℃以下 ,随温度的升高 ,病死率增加 ,幼虫病死速率加快 ,病死持续时间缩短 ;该病毒的热抑制温度在 2 7℃左右。改进的Schoolfield模型、Stinner模型可很好地描述幼虫病死速率与温度关系。甜菜夜蛾种群饲毒后的每日病死率可用时间 -剂量 -死亡率模型较好地拟合 ,模型模拟值与实测值有较好的吻合 (Hosmer- L em oshow统计量检验不显著 ) ,方程中各项系数经 t检验达极显著水平 ;不同温度下的幼虫累计病死时间分布可用 Weibull模型、Gompertz模型及 L ogistic模型拟合 ,模型经 F检验显著 ,模型中各系数经 t检验均达到或接近显著水平。用剩余平方和 Q比较各模型的拟合程度 ,以 L ogistic模型拟合最好 ,Gompertz模型次之 ,Weibull模型拟合效果稍差。上述模型可以用来模拟分析不同温度下的幼虫病死时间分布和幼虫病死速率。
Abstract:Spodoptera exigua is one of the most important pests of vegetable plants grown in China, feeding mainly on the foliage and damaging the fruits. It was reported that the parasitoids and a nuclear polyhedrosis virus had a notable impact on the larvae of Spodoptera exigua——the virus is the most effective mortality factor. Epizootics in natural populations usually occurred and the temperature was one of the most important environmental factors affecting epizootics. In this paper, based on the systematic observa...