The Study Of Dynamics On Integreted Pest Management Models With Virus Infection

With the development of agriculture and forestry,single chemical control or biological control exists some disadvantages for pest control.Therefore,it is necessary to control pest with the integrated pest management from the whole viewpoint of biology and environment.Based on the theory of population dynamics,infectious disease dynamics and impulsive differential equations,integrated pest management models with viral infection are established in this thesis.The dynamical behaviors of the system are discussed through the theory of Floquet multiplier and the comparison theorem of impulsive differential equations,and the numerical simulation is given.The full text is divided into three chapters:The first chapter summarizes the background and present status of the research.And also briefly introduces the main research contents some preparatory knowledge of this thesis.In the second chapter,the integrated pest management models based on impulse control are established.The global stability of the periodic solution of extinction under different control measures is discussed respectively.Combined with the numerical analysis,discussed the influence of corresponding parameters for the threshold that affects the stability of pest extinction periodic solution,and obtain the key factors affecting the pest control.When the application of natural enemies is more frequent than the insecticides,the more frequent natural enemies are released,the better the control effect of pests;when the application of insecticide is more frequent than the natural enemies,there is an optimal number of spraying pesticides under certain conditions.The conclusion could provide some suggestions for the design of optimal pest control strategies.In order to avoid the influence of chemical insecticides on environment,the third chapter applies biological insecticides instead of chemical insecticides to control pests in the proposed model on the basis of the second chapter.The consistent existence of the model and the stability of the pest eradication periodic solution and the sufficient conditions for the existence of the positive periodic solution of the system are discussed.Finally,regarding the intrinsic growth rate as the bifurcation parameter,we demonstrated the complex phenomena of the system.