Dutch Elm Disease - Ophiostoma novo-ulmi

This disease has been in the UK for over 50 and in this time has changed much of the landscape. It was accidentally imported from Canada an although the spread has slowed it is still moving North through the country.

 

It is not a disease is caused by Elm Bark Beetle which bores through the elm bark.

 

The first sign of infection can usually be seen in the top part of the tree in the upper branches which begin to wither and turn yellow in the summer when they should be green. This slowly spreads throughout the tree until eventuality the root dies.

 

If you peel the bark from an infected part of the tree you will see the dark streaks left by the beetle  or if you cut the wood you can see dark rings or spots in the cross section of the timber.