Ophiostoma novu-ulmi

Description

Elm bark beetles are responsible for the spread of Dutch Elm Disease. The bark beetles spread the spores of DED when they bore into the inner bark of stressed elm trees. Once infected, the fungus kills the network of transport cells in the tree. Infections can spread rapidly through the tree leading to mortality within several years.

Symptoms & Diagnosis

Symptoms of DED usually begin with one branch and eventually involve the entire canopy. Early symptoms may include wilted leaves and sparse foliage in the spring. These leaves may later turn yellow/brown and drop during the summer months.

Treatment

Controlling Dutch Elm Disease begins with controlling Elm Bark Beetles. Preventive treatments can be applied to keep bark beetles from boring into the tree. Further control can be gained with soil applied treatments to gain higher levels of protection.

Management

Managing tree stress is a crucial component of disease management. Trees can remain healthier and aesthetically pleasing longer by properly managing water, avoiding compaction and grade changes, and controlling insect damage. Fertilization improves tree vigor.

Affected Species

• Ulmus spp. (Elm Trees)