Spotted wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae: Drosophilini) is a global pest attacking ripening small and stone fruits. Laboratory studies were conducted to determine temperature-dependent survival and fecundity of SWD. A temperature-dependent matrix model using these data was applied to determine if population pressure of D. suzukii could be predicted based upon environmental conditions. As an example, different pressure levels were found in two distinctly different seasons in the Willamette Valley of Oregon. The model was also applied to determine the effects of population factors such as regional climatic differences, microclimates, bacterial infection and parasitism. The population model is an additional tool for SWD risk-prediction. Pest management practitioners can make timely management decisions as the crop ripens using this model. The limitations and benefits of using this model are discussed