Susan Katzell, an urban forester working for the City of Red Deer, routinely inspects sticky traps positioned high on trees throughout the city. Her main focus is on identifying banded elm bark beetles, which are the primary carriers of Dutch elm disease (DED).
The recent confirmation of another DED case in Edmonton has struck a chord with Katzell, as this deadly fungus poses a significant threat to all types of elm trees in Alberta. With Edmonton’s total cases reaching 17 since 2024, Katzell emphasized the importance of heightened monitoring efforts. She highlighted that the transportation of firewood is a common way for infected beetles to spread over long distances.
Describing the beetles as small and elusive, Katzell explained their emergence from diseased wood and potential transfer to healthy trees for infection. She underscored the crucial role of elm trees in the city’s urban landscape, constituting about 10% of the canopy in urban parks and streets.
Janet Feddes-Calpas, the executive director of the Society to Prevent Dutch Elm Disease (STOPDED), estimated that DED puts around 900,000 municipal elms in Alberta at risk, with a total canopy value of approximately $2 billion. Feddes-Calpas mentioned that yellowing and wilting leaves typically serve as early indicators of DED presence.
STOPDED, a provincial non-profit organization, coordinates disease surveillance across 122 Alberta municipalities. Feddes-Calpas explained that DED infiltrates a tree’s vascular system, obstructing water and nutrient flow and ultimately killing a mature tree within a year.
Although Alberta and Newfoundland and Labrador maintain an official DED-free status in Canada, Feddes-Calpas noted that Alberta municipalities have been vigilant since two DED cases surfaced in Lethbridge in 2020. She added that the expanding DED cluster in Edmonton has further heightened concerns among these municipalities.
Emphasizing the significance of elm trees in Alberta’s municipal tree canopies, Feddes-Calpas highlighted the use of sticky traps near elm trees as the primary defense mechanism to detect DED. Katzell affirmed the active deployment of sticky traps and surveys in Red Deer to monitor signs of DED, such as yellowing leaves.
Feddes-Calpas detailed that if a DED case is detected, a provincial response plan is activated. This plan involves immediate removal, debarking, and inspecting trees within a one-kilometer radius multiple times in a season to contain the outbreak.
To prevent beetle influx from neighboring regions like Saskatchewan, STOPDED has placed signs at provincial border entrances cautioning against bringing firewood. Along the U.S. border, Feddes-Calpas indicated collaboration with customs officials to confiscate firewood from travelers, ensuring proper disposal methods to curb DED spread.
Red Deer resident Susan Knopp, residing in a neighborhood lined with mature elms, expressed sentimental attachment to the trees that have been an integral part of her family’s life. Knopp highlighted the trees’ aesthetic and functional benefits, providing cooling shade during hot summer days.
Katzell mentioned Red Deer’s support to neighboring municipalities by setting up elm traps in communities like Sylvan Lake and Elnora, as well as local campgrounds susceptible to outside firewood transport. As seasonal monitoring continues, Katzell stressed the importance of residents being aware of the prohibition on elm tree pruning in Alberta until September 30 as a preventive measure and encouraged prompt reporting of any signs of wilting leaves to the municipality.