Research On Pest Control Under The Influence Of Dynamic Factors

Pests have always been an inevitable problem in crop production,and how to control pests effectively is essential.Over the years,spraying pesticide has been the most commonly used method of controlling pests.Owing to the fact that pesticide's killing pests is not an instantaneous process,but a long-term,unquantifiable and dynamic one,we need to consider the residual effect of pesticide when the pest control model is established by using pesticide effect function to simulate the residual process of pesticide.Against the fore-mentioned biology background,in this paper,a class of integrated pest management SI model combined with biological control and chemical control with different frequencies is established.In the first chapter,the biology background and the current situation of the development are systematically introduced.The present paper categorizes pests as infected ones and susceptible ones and assumes that the enemy only hunt susceptible pests,and a pulse control predators-pests model is established.Pesticide effect function is introduced to depict the pesticide residual effect in the model,considering that the pesticide is sprayed into the environment,then the pesticide acts on the pests and enemies,it conforms to the pollutant discharge model of inputting poison in the form of pulse,and the two kinds of models are reasonably nested for manifesting the influence of the pesticide effect function on pests and natural enemies.In the second and third chapters,the stability of the susceptible pest extinction periodic solution is studied and analyzed under different circumstances(the frequency of spraying insecticide is higher than that of releasing natural enemies and infected pests,and the frequency of releasing natural enemies and infected pests is higher than that of spraying insecticide).A sufficient condition for global asymptotic stability is given,and the correctness of theoretical result is verified through the numerical simulation analysis.By researching the influence and sensibility analysis of the changed parameter to the critical value,we obtain the optimal frequency of spraying pesticide(or the optimal frequency of releasing natural enemies and infected pests)and the correlation of main parameter to the critical value.