This is a reminder to check your elm trees for DED symptoms. All species of elm trees in Alberta are susceptible to DED. If a tree is infected with this fungus it must be removed immediately to prevent further spread.

Symptoms of DED infection are leaves initially wilting followed by curling, turning yellow and then brown. This is also referred to as flagging. Leaf symptoms are usually accompanied by brown staining under the bark. Suspicious elms must be tested at a lab for the presence of the fungus. Lab costs are covered by STOPDED.

The fungus is primarily spread from one tree to another by elm bark beetles. The beetles are attracted to weak and dying trees, which serve as breeding sites for the beetles. Once the beetles have pupated and turned into adults they leave the brood gallery and fly to healthy elms to feed, thus transporting the fungus on their bodies from one tree to the next. STOPDED monitors annually for the vectors throughout the province. In the last years, elm bark beetle numbers have not only increased, but the number of municipalities, especially along the AB/SK border, finding beetles is also increasing.

For this reason, it is important that elm firewood not be transported into or within Alberta as the wood may be harboring the bark beetles. Firewood is confiscated at all the Alberta-Montana border crossings.

All elm trees that are showing DED symptoms must be reported immediately. To report symptoms or for more information call the toll free provincial STOPDED hotline by dialing 1-877-837-ELMS(3567). You can also visit our website at

Janet Feddes-Calpas
STOPDED Executive Director
STOPDED Hotline: 1-877-837-ELMS