Tree-lined boulevards were turned into treeless streets. Since 1981, four cases of DED have been found in Regina. In 1991, a number of trees in Sherwood Forest, just west of the city, were found to be infected. DED is caused by a fungus. Once a tree gets the disease, the fungus blocks the water-conducting tubes which carry water from the roots to the limbs and leaves.
Nothing gets through.
In an elm, that means that the leaves wilt or flag, and eventually die. They may turn yellow or brown well before fall. T he fungus is spread from tree to tree by elm bark beetles. The beetles burrow under the bark or enter cuts or wounds. Fungus spores are carried into the uninfected tree.