The beet armyworm has become a widespread cotton pest, causing great damage in some areas. Many questions relative to the occurrence of this pest and the factors regulating its population dynamics remain unanswered. At least four strongly interacting circumstances contribute to beet armyworm outbreaks: (1) the presence of beet armyworm populations, (2) suitable conditions in the field and in the quality of the plants in the field for development and survival of the beet armyworm, (3) appropriate weather conditions, and (4) insecticide history of the field or region. Further work is needed in each of these areas to define the levels and components of the several factors that create or detract from outbreaks. It is clear, however, that the beet armyworm is an induced pest, and that efforts to conserve the natural enemies of this pest will result in at least partial, if not complete, control.