Although experienced modelers are usually aware of the dangers and benefits of the use of models in applied entomology, many scientists who may use models are not. Although some remain skeptical that models serve any useful purpose, others have unrealistic expectations about the information that models can provide concerning a particular problem. Models are often incorporated in the decision-making framework of expert systems in which their limitations may be hidden. Government spending cuts and cost recovery policies in some countries force vigorous promotion of management systems by scientific advisory staff. Such uses can lead to unreasonable claims and expectations about the realism of answers provided by models. Here, the definition of a model is reviewed, a brief history of model uses in ecology is presented, and the limitations of such uses are discussed. In pest management, the very real benefits and dangers of using models will not be fully appreciated until objectives are clarified and limitations of specific models are discussed openly in published work.