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Toronto-Mississauga rids itself of the Asian long-horned beetle
July 20, 2020
Jane Stevenson

It’s been a 17-year-battle but the fight against the invasive Asian long-horned beetle appears to be won in Toronto and Mississauga.

The shiny black bug with white-spotted backs, measuring the length of an AAA battery, kills maple and other hardwood trees over a several-year period.

“It was first discovered in 2003,” said Taylor Scarr, director of integrated pest management at the Great Lakes Forestry Centre in Sault Ste. Marie, Ont.

“But the infestation had been sitting there since at least 1998 or before.”

Native to China and the Korean peninsula, the insects lay eggs in hardwood trees. After hatching, the larvae eventually bore into the centre of the trees, killing them over several years.

The beetle -- a major threat to the maple syrup industry -- likely arrived via wooden shipping crates, added Scarr.

Now any wooden crates coming from outside North American are required to be heat-treated to kill anything they might contain.

“So there’s still the threat of this insect coming in some other way,” said Scarr. “And there was a discovery, an interception in 2019 in a warehouse in Edmonton of Asian long-horned beetle, obviously some wooden crates were brought in.”

Spearheaded by the Canadian Food Inspection Agency, the coordinated effort to get rid of the beetle was also done with help from some U.S. agencies.

“There was a large aggressive control program with surveys and cutting down trees and chipping the trees to eradicate the insect,” said Scarr. “So the plan then was to cut down any infested tree and then any host tree that was within 400 metres would also be cut and chipped because we know the surveys don’t find 100% of the infested trees.”

Scarr said around 28,000 trees were cut and chipped between 2003-2005 with the last infested tree was found in 2007. In the spring of 2013, the Asian long-horned beetle was declared eradicated only to be found again later in the year.

“In both cases, they were actually found on cars,” he said. “And that was in Mississauga about eight kilometres from the last known infested tree in Toronto-Vaughan. So that initiated a second eradication program (in the winter of 2014) and this time all the infested trees were cut.”

The beetles have now been declared eradicated.

“It could come back,” cautioneed Scarr.