The emerald ash borer beetle has arrived in Winnipeg, jeopardizing more than 350,000 ash trees and potentially costing the city millions of dollars.

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This article was published 7/12/2017 (1455 days ago), so information in it may no longer be current.

The emerald ash borer beetle has arrived in Winnipeg, jeopardizing more than 350,000 ash trees and potentially costing the city millions of dollars.

That’s according to city forester Martha Barwinsky, who confirmed ash borer larvae were found in the Archwood neighbourhood of St. Boniface on Nov. 30.

The arrival of the beetle has the potential to wipe out the entirety of Winnipeg’s ash tree canopy, at a time when the city is struggling to keep up with the spread of Dutch elm disease.

"We anticipate there will be a significant impact on our urban canopy as a result of this pest... It is a serious problem," Barwinsky said at a press conference Thursday afternoon.

"Our canopy is at risk. We not only have Dutch elm disease, but now we have the emerald ash borer to manage. When we look at the percentage of elm and ash on boulevards and parks, we have 60 per cent of our canopy."

Winnipeg could lose the entirety of its ash tree population over the next ten years, according to the city. That would wipe out 30 per cent of all boulevard and park trees, which are valued at $437 million.

During the larval stage the ash borer feeds on the tissue below the bark of ash trees, eventually stopping the flow of nutrients and causing it to die.

The invasive species – introduced to North American from China — has already decimated millions of hectares of ash trees in the U.S. and Ontario.

At this point in time, it remains unclear how or when the beetle was introduced to Winnipeg, as well as how severe the infestation is. The city will be rolling out a survey over the coming month to determine the extent of the beetle’s presence in Winnipeg.

Following that, a report will be given to city council so funding for a treatment plan can be approved.

But, now that the ash borer is here, it's here to stay. All the city can do is attempt to manage the mortality rate of the ash tree canopy.

"Treatment is an injection... into the trunk. It’s conducted every two years to help preserve and protect that ash tree. It’s not 100 per cent that it will save the tree, as the beetle could have done more damage to the tree than we are even aware of," Barwinsky said.

"One of the characteristics of the emerald ash borer that makes it so serious is that it’s very difficult to detect. Even for us to detect this tree it took some time to inspect the tree and look for the signs and symptoms."

The city will not be treating ash trees on private property. People with ash trees on their property should look for general decline in the tree, exit holes from the beetle and significant woodpecker activity.

"We are taking this very seriously — 30 per cent of our trees in the city are ash," Sustainable Development Minister Rochelle Squires said in an interview.

Squires said she and her predecessor Cathy Cox have been very concerned with the possible arrival of the ash borer, and have signs posted at all border entry points to the province warning drivers to unload any ash wood they may be carrying.

Dealing with the ash borer "is a very significant challenge," but how to combat it is better left to her department’s experts, she said.

When asked if her department has the resources it needs to manage the ash borer beetle, Barwinsky said, "Well that will be part of the report that’ll be going forward to council... We don’t know, yet (how much it will cost)... It will cost millions. It’s costly."

She went on to say it’s important the city doesn’t lose sight of the resources still needed to combat the spread of Dutch elm disease.

While the elm tree canopy can still be saved, the city can only try to mitigate and control the loss of the ash tree population.

How long the city’s survey will take depends on how extensive the infestation is. Once it’s complete, a report will be submitted to council and eventually a treatment plan rolled out.

"We are just looking at managing it over an extended period of time in order to reduce the losses and spread the losses and the cost over that time," Barwinsky said.

"We’re concerned about everywhere in the city. We’re concerned, but we’re not giving up. I’m hopeful that we definitely will have canopy in Winnipeg and we’re doing the best we can to make sure that we do."

--- with files from Nick Martin

Ryan Thorpe

Ryan Thorpe

Ryan Thorpe likes the pace of daily news, the feeling of a broadsheet in his hands and the stress of never-ending deadlines hanging over his head.