To date, the widespread planting of Bt crops has resulted in pest resistance for only a small subset of all pest populations managed by this technology. However, these recent cases suggest a need to develop more integrated management solutions for pests targeted by Bt crops. A common pattern observed among problem fields in this study was the consecutive planting of the same type of Bt maize over several seasons. Even with resistance management plans in place, sole reliance on Bt crops for management of agriculture pests will likely hasten the evolution of resistance in some cases, thereby diminishing the benefits that these crops provide.