Corp Comm Connects

Guelph asks residents to join the fight against the emerald ash borer
May 26, 2015
By Vik Kirsch

Its luminescent green body may be strikingly fascinating to look at, but the emerald ash borer is a destructive menace the municipality is battling under a canopy of thousands of at-risk trees.

"All of it is threatened, as they are in other municipalities," Guelph urban forestry field technologist Timea Filer said Tuesday, appealing to residents to take action alongside the city.

"A lot of people don't recognize they have ash trees and what the risks are."

That threat originated on the other side of the planet, in an era of global trade where goods have few boundaries - as do the bugs that tag along in wood crates and forest products.

The emerald ash borer takes a particular liking to ash trees of all kinds in the broad genus fraxinus.

"That's its native host in Asia," Filer said. But it's been spreading widely. It was first seen in Canada in 2002, and the Guelph area almost a decade later.

The city anticipates the pest, which bores under bark and feeds, will kill almost all the thousands of ash trees here, unless they're protected. The current preferred treatment is a pesticide with the brand name TreeAzin administered by qualified technicians.

Filer said some cities have lost almost all their ash trees, though there's been some success with the pesticide.

Guelph is treating the healthiest ash trees on municipal property to give them a shot at resisting the borer. She estimates there's 10,000 such ash trees on city properties, with about 1,200 slated for treatment, or about 500 or so this year alone. The number of trees to be treated this year is being assessed now.

"That's yet to be determined," Filer said.

Residents, she said, should have ash trees on their private properties identified and assessed by experts. There are two options for infested trees.

"Either treat or remove," Filer said.

If infested and not treated, the chances are they'll die.

"It's a very high likelihood," she said.

She's advising residents to contact qualified tree specialists. She's also available for those with questions, and can be reached at city hall, she said.

Filer added information on how to identify ash trees and the nefarious emerald ash borer is on the city's web site, as well as other helpful sites like and the Canadian Food Inspection Agency, focused in part to protection of trees and smaller plants.

A city bulletin this month regarding the ash borer issue asserts that property owners are responsible for managing any ash borer infestation on their property. It also reminded that the City's Tree By-law may affect tree removal on properties larger than 0.2 hectares and a tree removal permit may be required.

"Property owners may be eligible for an exemption from a tree removal permit if the tree is found to be infested," it states.