Disease Note

Dutch Elm Disease (Ceratocystis ulmi) in Utah. F. A. Baker, Department of Forest Resources, Utah State University, Logan 84322. S. V. Thomson, Department of Biology, Utah State University, Logan 84322; B. M. Tkacz, USDA Forest Service, Forest Pest Management, Ogden, UT 84401; and E. L. Hobbs, Department of Botany, Weber State College, Ogden, UT 84401. Plant Dis. 70:694. Accepted for publication 11 March 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-694e.

Dutch elm disease was first found in dying American elms (Ulmus americana L.) in Salt Lake City, Utah, in March 1982. The presence of Ceratocystis ulmi (Buism.) C. Mor. was confirmed by isolation. Dutch elm disease is now known to exist in Box Elder, Cache, Davis, Salt Lake, and Weber counties. Although the native elm bark beetle, Hylurgopinus rufipes Eichhoff, is present in Utah, the smaller European elm bark beetle, Scolytus multistriatus (Marsham), is most commonly associated with the disease. Because American elms make up only a small proportion of Utah’s shade tree population, Dutch elm disease will have a minimal impact. In areas with highly valued elms, or where American elms are abundant, sanitation and root graft disruption are being used to reduce losses. The presence of Dutch elm disease should not preclude the judicious planting of American elms in Utah.