What tree disease was spread to north America by a fungus carried in insects embedded on wood imported from northern Europe?

Answer 1

The tree disease that spread to North America is known as Dutch elm disease. It is caused by a fungus, specifically Ophiostoma ulmi, which is transmitted by bark beetles that infest elm trees. This disease devastated elm populations across the continent after its introduction in the early 20th century due to the importation of infected wood from northern Europe. Efforts to manage and control the spread have been ongoing but challenging.