The host plant for Dutch elm disease is any tree belonging to the elm family (Ulmaceae). This devastating fungal disease primarily targets various species within this botanical family.
Understanding the Host
Dutch elm disease (DED), caused by the fungi Ophiostoma ulmi and Ophiostoma novo-ulmi, specifically infects and thrives within the vascular system of elm trees. The disease is typically spread by elm bark beetles, which carry fungal spores from infected trees to healthy ones.
Key characteristics of the host plants include:
- Elm Family (Ulmaceae): All species within this family are potential hosts, encompassing true elms (Ulmus species) and sometimes even closely related genera.
- Vascular System: The fungi colonize the tree's xylem, the water-conducting tissues, leading to wilting and eventual death.
Susceptibility Among Elm Species
While all elms are susceptible to Dutch elm disease, their levels of vulnerability can vary significantly.
| Elm Host Category | Description | Susceptibility Level |
|---|---|---|
| Native Elms | Elm species indigenous to regions where DED has been introduced, such as American elm (Ulmus americana). | Most Susceptible |
| European Elms | Varieties like English elm (Ulmus minor 'Atinia') and Wych elm (Ulmus glabra). | Highly Susceptible |
| Asian Elms | Species like Siberian elm (Ulmus pumila) and Chinese elm (Ulmus parvifolia). | More Resistant |
| Hybrid Elms | Cultivars developed from crossing resistant Asian elms with susceptible European or American elms. | Moderately Resistant |
Native elms, such as the once ubiquitous American elm, are particularly vulnerable, often succumbing rapidly to the disease. Their lack of natural resistance to the introduced fungal strains made them highly susceptible to the widespread devastation seen across continents.
For more information on Dutch elm disease and its impact, you can refer to resources from university extensions and forestry services, such as this overview from the University of Wisconsin-Madison Extension.
