Fall armyworm, Spodoptera frugiperda (J.E. Smith) is one of the most destructive maize pests in the tropical zone of the American Continent and recently has been reported in several countries in Africa and Asia. This species is highly polyphagous and can cause significant yield losses in maize and cotton crops under moderate-high infestations. Historical S. frugiperda management in South America relied on plant protection with synthetic insecticides, ranging from 1-10 applications per crop cycle, depending on pest pressure and crop system management. However, this strategy has not been satisfactory in many situations because of larval feeding site and the biotic potential of this species. More recently, genetically modified maize plants expressing insecticidal Bt proteins gained significant role in managing this pest in the region due to its effectiveness. Nonetheless, local environment, landscape, and agricultural practices can create intense selection pressure favoring resistance development to both chemistries and biotech control tools, representing a significant challenge to effective long-term control of this pest in maize and other important crops. Interestingly, incidence of S. frugiperda has significantly increased in soybean fields in the last few years in Brazil, likely due to the widespread adoption of Bt varieties not targeting its control, highlighting its ability to adapt to environments and invade potential empty niches. Understanding regional landscape, pest ecology and genetic variability is fundamental for establishment and deployment of effective, locally adapted practices, and the utilization of a variety of control tactics is a key strategy for sustainable management and cropping systems.
