Ceratocystis fagacearum is a fungal pathogen that primarily affects oak trees, causing a disease known as oak wilt. This fungus invades the vascular system of the trees, disrupting water and nutrient transport, which can lead to wilting and eventual death. It is particularly harmful to species like red oaks and white oaks. The spread of Ceratocystis fagacearum occurs through root grafts between trees and by insects, especially sap-feeding beetles. Management strategies include removing infected trees and preventing root connections. Early detection and intervention are crucial to controlling the spread of this destructive pathogen in forest ecosystems.