Wall R, Smith K E, Berriatua E, French N P
Insect Ecology and Parasitology Group, School of Biological Sciences, University of Bristol, UK.
Vet Parasitol. 1999 Jun 30;83(3-4):253-64. doi: 10.1016/s0304-4017(99)00062-x.
The pattern of population growth of the ectoparasitic mite, Psoroptes ovis (Acari: Psoroptidae), on its ovine host is considered through the development of a Leslie matrix-based, simulation model. The model is parameterised using experimental data in conjunction with reanalysis of published data. The model shows that on sheep P. ovis populations grow at a rate of approximately 11% per day and the population doubles every 6.3 days. Additional rates of adult mortality, in excess of 50% per day, need to be imposed to prevent population growth. The predictions of the model are tested by comparison of the expected numbers of mites with the numbers recorded in lesions either on naturally infested sheep where the date of infestation can be estimated or on one artificially infested animal, where the initial number of mites and date of infestation are known precisely. In both cases the observed number of mites in lesions relate closely to the numbers expected from the simulations. The model simulations do not support the concept of a 'lag' phase as distinct from the 'growth' phase in the changing pattern of mite abundance on an infested sheep and suggests that the observed pattern of growth is a natural function of an exponential increase in numbers. The development of such models and their use in explaining the demographic processes which drive mite population dynamics are discussed.
通过构建一个基于莱斯利矩阵的模拟模型，来研究体外寄生螨——绵羊痒螨（蜱螨亚纲：痒螨科）在其绵羊宿主上的种群增长模式。该模型通过结合实验数据和对已发表数据的重新分析来进行参数化。模型显示，在绵羊身上，绵羊痒螨种群以每天约11%的速度增长，种群数量每6.3天翻一番。需要施加超过每天50%的额外成虫死亡率，以防止种群增长。通过将预期螨数与在自然感染绵羊（可估计感染日期）或人工感染动物（已知螨的初始数量和感染日期）的病变中记录的螨数进行比较，来检验模型的预测。在这两种情况下，病变中观察到的螨数与模拟预期的数量密切相关。模型模拟不支持在受感染绵羊上螨数量变化模式中存在与“增长”阶段不同的“滞后”阶段这一概念，并表明观察到的增长模式是数量指数增长的自然函数。本文讨论了此类模型的开发及其在解释驱动螨种群动态的人口统计学过程中的应用。
