Pest - Natural Enemy Ecosystem-based Pest Control Problem

It is well known that pest outbreak can cause economic loss and pest control has been concerned by entomologist and society. A wide range of pest control strategies is available to farmers. Integrated pest management (IPM) is a long term management strategy that uses a combination of biological, cultural and chemical tactics that reduce pests to tolerable levels, with little cost to the grower and minimal effect on the environment. IPM has been proved by experiment that it is more effective than classical one, such as biological control or chemical control. The main purpose of this paper is to analyze and compare the effects of two releasing methods of natural enemies on pest control and dynamical behavior of proposed systems.In the second chaper of this paper, we consider a predator-prey model which has an impulsive reduction of the pest population density by catching or by poi-soning with chemicals and an impulsive increase of the predator population density by artificial breeding or releasing some species. To release natural enemies, many works have considered the model with an impulsive increase only by a constant. In present paper the different releasing methods including constant and proportional to the predator density are considered and analyzed. Further, the effects of those releasing methods of natural enemies on integrated pest management strategy are investigated. The results obtained in this Chapter indicate that the proportion releasing predator has strong effect on the dynamical behavior of the model with economic threshold.Holling-I type predator-prey model including integrated pest management (IPM) interventions with impulsive effects at both fixed and unfixed times were analyzed in the third chaper. For the model with fixed impulsive effects, the global stability of pest eradication periodic solution and the dominance of dynamic behavior were investigated. For the model with Economic Threshold, analytically investigation system is impossible, so we turn to use numerical studies. Numerical investigations clarify that the dynamical behavior of the system is quite complex, which means that the application and realization of IPM in practice are very difficult.