Catastrophe Control Of Wheat Aphid Ecosystems Based On Washout Filter

Aphid populations are an important pest of wheat production in China and the world.Aphid populations have a short life cycle,high fecundity,which leads to frequent outbreak.The outbreak has devastating damage to wheat aphid ecosystems,which would amount to millions of dollars per year.In this paper,the ecological mechanism of the outbreak of wheat aphid populations is analyzed from the perspective of catastrophe theory.Combined with the catastrophe control theory,some management strategies of pest populations are proposed to ensure the stable yield of wheat.The specific contents are as follows:Part Ⅰ,Catastrophe theory and its applications in ecology are introduced.And the origin,application and development of catastrophe control theory are introduced,too.Part Ⅱ,Some preliminaries are given for the later use.Part Ⅲ,On the basis of the one-dimensional Logistic model,fold catastrophe model and Allee effect model,considering the effect of enemy populations on wheat aphid populations,the corresponding control models with washout filter are proposed and the catastrophe controllers are designed to keep the aphid populations at the refuge level as soon as possible.Finally,some simulations are carried to show the feasibility and effectiveness of the controls.Part Ⅵ,Based on the two-dimensional population model of wheat aphid ecosystem,considering the effect of environmental factors on wheat aphid populations,the corresponding model of wheat aphid ecosystems with delay is built.The model is analyzed using the stability theory of differential equations and catastrophe theory.For the outbreak phenomenon of wheat aphid populations,the corresponding control model with washout filter is given and the catastrophe controller is designed to make wheat aphid ecosystems in a virtuous cycle.The study of the paper may provide the reference for the effective management of pest populations.