多种病原物混合侵染的昆虫流行病模型

Mathematical Models to Describe Mixture Infection of Multi-Species Pathogens to Insects

两种或两种以上的病原物同时侵染昆虫寄主时，病原物之间的相互作用表现为偏利、偏害、中性及竞争等类型，寄生群体的病症可呈多种形式．根据单种病菌的重叠侵染原理，建立了多种病原物混合侵染时以温度、病原接种量、虫龄及湿度为因子的昆虫流行病模型．由模型可计算寄生群体中不同病原物的致病比率，及寄主群体的总发病率，给出了模型的参数求解算法，以及病原物相互作用类型的判定准则．这类模型可用于多种病原物混合侵染的昆虫流行病预测，也可作为多种病原物混合施用防治害虫的最优化模型．

When insect host has been infected with more than one species of infectious pathogens,the interactions between different pathogens will be emerged as the types of mutualism,competition,etc.,and the infection symptoms in host population will be divergent.According to the overlapping infection theory,the mathematical models to describe mixture infection of multi-species pathogens which takes the temperature,inoculum number,insect instar,and moisture as driving variables,have been developed in this paper.The symptomatic incidence of every species of pathogens,and the total incidence in a host population can be derived from the models.The algorithms to calculate the parameters in the models,and the criteria to determine the interactions between different pathogens have been given.