Dutch elm disease
(Ophiostoma ulmi)
This species is Introduced in the United States
Major Hosts:
Elms, especially American elm
Key Features:
Disease: Fungus carried on elm bark beetles, which are attracted to stressed trees. The fungus also often spreads by root grafts. No visual fruiting bodies (e.g. mushrooms) will be seen in the field. Fruiting bodies will be seen only under the microscope in the laboratory.
Damage: Wilting, yellowing, and browning of the leaves on flagged branches. Dying branches may have dark streaks in vascular tissue just under the bark. Death of a tree may occur within one year but will vary based on environmental conditions.
Control/Management:
Insecticide treatments are not effective. Preventative fungicide treatments are an option to protect high-value trees. Trenching in order to disrupt root grafts between elms is also an option.
Elms, especially American elm
Key Features:
Disease: Fungus carried on elm bark beetles, which are attracted to stressed trees. The fungus also often spreads by root grafts. No visual fruiting bodies (e.g. mushrooms) will be seen in the field. Fruiting bodies will be seen only under the microscope in the laboratory.
Damage: Wilting, yellowing, and browning of the leaves on flagged branches. Dying branches may have dark streaks in vascular tissue just under the bark. Death of a tree may occur within one year but will vary based on environmental conditions.
Control/Management:
Insecticide treatments are not effective. Preventative fungicide treatments are an option to protect high-value trees. Trenching in order to disrupt root grafts between elms is also an option.
Resources
- Insects and Diseases of Trees in the South - USDA Forest Service
- How To Identify and Manage Dutch Elm Disease - USDA Forest Service
- How to Save Dutch Elm Diseased Trees by Pruning - USDA Forest Service
- Fungicide Injection to Control Dutch Elm Disease: Understanding the Options - USDA Forest Service
Selected Images
Invasive Listing Sources
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Fungi |
| Phylum: Ascomycota |
| Subphylum: Pezizomycotina |
| Class: Sordariomycetes |
| Subclass: Sordariomycetidae |
| Order: Ophiostomatales |
| Family: Ophiostomataceae |
| Genus: Ophiostoma |
| Ophiostoma ulmi |
References
Common Name Reference: Hansen, E.M. and K.J. Lewis. 1997. Compendium of Conifer Diseases. APS Press. 3340 Pilot Knob Road, St. Paul, MN 55121-2097. 101 pp.
Scientific Name Reference: Index Fungorum. Paul Kirk. CABI, CBS and Landcare Research. http://www.indexfungorum.org/