Agricultural issues with climate change—case studies with corn pests: tar spot of corn (Xylariales: Phyllachoraceae), corn earworm (Lepidoptera: Noctuidae), and itchgrass (Poales: Poaceae)

Abstract Agricultural production and crop yields are threatened around the world by the emergence and spread of agronomic pests, including insects, diseases, and weeds. Due to changes in precipitation, carbon dioxide levels, and warming temperatures being experienced throughout most of the world, new challenges are emerging for pest management in virtually all major cropping systems. While precise environmental impacts due to climate change are very difficult to predict, farming in the future will require new and innovative solutions for pest management. In this article, we explore the challenges of 3 problem pest species commonly found in corn cropping systems: tar spot of corn (Phyllachora maydis Maubl.), corn earworm (Helicoverpa zea Boddie), and itchgrass (Rottboellia cochinchinensis). These cases illustrate how fungal pathogens may become more aggressive with changing moisture patterns, how insect pests may shift range and increase in generation number under warming temperatures, and how invasive weeds may gain competitive advantages under elevated CO₂. Understanding how pests respond to climate pressures is crucial for developing the innovative agricultural strategies needed to manage them in the future.