Technical Abstract: In the past, the dominant approach in theoretical pest management ecology has emphasized the use of simple analytical or mathematical models and the analysis of systems in equilibrium. Recent advancements in computer technology have provided the opportunity for ecological insect modelers to move away from this dominant approach and create new methodologies for explaining population and community dynamics. The new approaches emphasize greater realism in the models and greater testing of the models in the field. Because ecological theory cannot be generally applicable without being realistic, true generality in a theoretical model is impossible without realism. Complex simulation models are often more accurate (realistic) and easier to relate to field situations than simpler analytical models. The creation of valid, complex numerical models for a few specific cases is a valuable step in the development of new theory. Greater access to supercomputers in the future will facilitate the use of complex numerical models that incorporate extensive ecological knowledge. In this chapter, the role of models in ecological- and insecticide-based pest control strategies are first discussed, followed by a description of the major types of insect/pests models available.