The Simulation Of Population Dynamics Of Sitobion Avenae And Rhopalosiphum Padi

Sitobion avenae(Fabricius)and Rhopalosiphum padi are the most damaging pests in winter cereals of china.Although the control strategy of high frequency pesticide spraying can effectively decrease the harm of wheat aphid,it can lead to the emergence of resistant population and increase the cost.The accuracy prediction of wheat aphid can determine the necessity and frequency of pesticide application and provide a powerful tool for scientific control.The following research was done to build widely used simulation model of cereal aphids reflecting ecological mechanism:1.The paper database about the effect of ecological factors on biological processes of Rhopalosiphum padi was constructed and each ecological factor was separated considered.We have already downloaded 43 papers which is about the effect of temperature,high temperature,host development stage,natural enemies and other ecological factors on biological processes.In the process of model construction,we regarded the model between average temperature and life-history traits as the basic model and incorporate the influence of other ecological factors through correction coefficient.2.The meteorological database of the field survey site of Rhopalosiphum padi was established and the validation of simulation model was checked.The field observation data of Wuhan and Xinxiang were sorted out in the form of excel table and the excel table contains survey date,cereal growth stage,the number of 1-3 apterous instars,the number of 4th apterous instars,the number of apterous adults,the number of 1-3 alate instars,the number of 4th alate instars,the number of alate adults,total number of aphids.The access meteorological database of the survey site was established which contains daily average temperature,daily maximum temperature,daily minimum temperature,daily rainfall and other information.The validation results of Wuhan and Xinxiang showed that simulated peak number is close to peak number,simulated peak day is close to peak day.The model accurately simulated the population dynamics of Rhopalosiphum padi.3.The relationship between extreme high temperature and biological process of Sitobion avenae was established.In high temperature model,the model between high temperature duration and biological process relationship was regarded as the base model,high temperature maximum,high temperature pattern were incorporated as correction coefficient.The effect of high temperature model was related to exposure stage.The results showed that longevity,lifetime fecundity and survival rate decreased with the increase of the duration of high temperature.When high temperature value exceeded 36 ?,the life performance quickly reduced.Continuous high temperature reduced the life performance more than discrete high temperature.4.The validation of simulation model of Sitobion avenae with high temperature model was checked.The fit of linear regression between simulated value and observation value of all sites is 0.6228.Simulated peak day,simulated peak number is close to peak day,peak number respectively in most years of different sites showing that model accurately simulated the population dynamics in most years.5.Population dynamics of Sitobion avenae(Fabricius)in winter cereal regions of china were analyzed.We organized the Peak Day,Peak Number of Sitobion avenae of five sites including Wuhan,Xinxiang,Anyang,Linfen,Beijing and used the non-parameter method to compare the difference between different sites.The result shows Peak Day and Peak Number decreased from north to south in chinaAs a whole,we realized daily population dynamic simulation of Rhopalosiphum padi accurately.The high temperature model describe the ecological effect of high temperature on Sitobion avenae(Fabricius)and the simulation model with high temperature model accurately simulated the dyanmics of Sitobion avenae(Fabricius).