Dutch elm disease can be transmitted from a diseased elm to an adjacent healthy tree through root grafts. Therapy for infected trees is questionable. Use of a fungicide-injection program is most beneficial to protect valuable specimen trees. Some hybrids and cultivars are resistant. Elm leaf beetle larvae feeding Lower surface of the leaf between the main veins is chewed off.
Smaller veins remain intact.
Damaged areas become brown. Formerly called elm phloem necrosis. During June and July, leaves roll upward, turn yellow or brown, wither and drop pre maturely. Death of tree is fairly rapid. Inner bark near trunk base is yellow to butterscotch colored.