The tree should be removed at the first sign of infection. Leaf Scorch Early to midsummer, leaves on a few branches have a marginal leaf burn of scorch. Symptoms increase on the leaves later in the summer. The line marking the boundry between dead and living leaf tissue is wavy and has a definite yellow halo. Leaves usually fall prematurely.
More branches become involved in following years.
Xylella fastidiosa Leafhoppers and spittle bugs carry the baceria from tree to tree. Infected trees may survive years. Severely affected trees should be removed since they are attractive to elm bark beetles which can carrying the Dutch elm disease fungus. Leaves yellow and wilt over the entire crown of the tree and fall prematurely in summer. Trees may die within 1 year.