斜纹夜蛾核多角体病流行的时间动态

Epizootic dynamics of Spodoptera litura nuclear polyhedrosi virus.

通过对感病幼虫进行跟踪观察 ,研究了病毒不同浓度处理下 ,斜纹夜蛾核多角体病的田间流行动态 .结果表明 ,在试验病毒浓度范围 ( 3 .1× 10 5～ 3 .1× 10 8PIBs·ml-1)内 ,幼虫大多在喷施病毒后第 4天开始发病 ,第 5～ 7天为发病高峰 ,第 5～ 6天开始病死 ,第 6～ 8天为病死高峰 .宿主现患高峰与发病高峰基本一致 .宿主种群发病和病死时间分布可用时间 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 Lemoshow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 ;现患时间分布经Holliday模型拟合 ,方程经F检验显著 ,方程中的各项系数达到或接近显著水平 .应用模型可以预测病毒不同浓度处理下的宿主当代种群每天发病、现患和病死率 .

Through investigation of tracking infected Spodoptera litura larvae,the epizootic dynamics of S.litura nuclear polyhedrosis virus(SlNPV)in field was studied with different dosages of SlNPV.The results showed that in the range of virus dosages (3 1×10 5～3 1×10 8 PIBs·ml -1 ),the initial infection syndrome was observed after 4 days of treatment,and peaked in 5～7 days.The larvae mortality occurred after 5～6 days of treatment,and peaked in 6～8 days.The prevalence peak of host was basically coincident to the incidence peak.The distribution of diseased incidence of hosts and disease death time could be quite simulated by time dosage mortality model(TDM).Hosmer Lemoshow test showed that the predicted values well fitted with observed data,and t test indicated the parameters of the model reached significant level(P<0 0001).The distribution of diseased prevalence was simulated by Holliday model,the regression of function was significant by F test,and the parameters of the model reached or approached significant level(p<0.005). TDM model could be used to predict the daily incidence,prevalence,disease death rate of present generation population of host pest.