Thanks for the query.
Dutch elm disease affects elm trees and is spread by the Elm bark beetle.The Elm trees are first affected on a branch with leaves withering and dying which ultimately spreads throughout the tree finally killing it. Although, the disease is spread by the beetle, it is caused by a form of sac fungi. The disease was thought to be native to Asia but accidentally got introduced in America and Europe. This disease also got introduced into New Zealand.
Source: Wikipedia
Disclaimer: I do not own any of the images. All images are copyrighted to their respective owners.