New Brunswick

Emerald ash borer destroys 10 large trees in Edmundston

The City of Edmundston plans to cut down 10 ash trees this week that it planted more than 30 years ago, because of damage caused by the destructive emerald ash borer.

City will cut the trees down this week, replace them with hardwoods in the fall

The City of Edmundston plans to cut down 10 ash trees this week that it planted more than 30 years ago, because of  damage caused by the destructive emerald ash borer.

The ash trees, located along Saint-François Street, in front of the Canada Border Services Agency office, are clearly showing signs that they are being attacked by the emerald ash borer, city officials said. (City of Edmundston)

"It's very unfortunate, but it was inevitable," Alain Laplante, an urban forester with the city's public works department, said in a statement.

Once the presence of the flying beetle was confirmed in the city in 2018, officials knew all ash trees were at risk, he said. The invasive insect has killed millions of trees across North America.

The adult beetle, which has a metallic emerald green back and bright green underbelly, lays its eggs on the bark of an ash tree.

After the eggs hatch, the larvae bore through the bark, feeding on the inner bark and outer sapwood, creating S-shaped tunnels that erode the tree's ability to feed.

When the beetles emerge, they leave D-shaped exit holes. Immature beetles feed on the foliage, creating irregular notches in the leaves.

A tree can be destroyed within one to five years, depending on the level of infestation.

Once the damage is detected, the insect has already left the area and is attacking trees elsewhere, according to experts.

The 10 trees, located along Saint-François Street, are clearly showing signs that they are being attacked by the the emerald ash borer, the release said.

The Canadian Food Inspection Agency stipulates that a tree with a dieback level above 30 per cent must be felled and destroyed.

Laplante said the 10 trees will be replaced with other hardwoods in the fall.

The emerald ash borer is an invasive beetle, which has few enemies to keep it in check. (Minnesota Department of Natural Resources/The Associated Press)

The emerald ash borer has been in Canada since at least 2002 but wasn't detected in the Atlantic region until it hit Edmundston. It has since spread across New Brunswick.

It poses no threat to human health but poses "a major economic and environmental threat to urban and forested areas of North America," the federal agency has said. 

Individual beetles can travel between 400 and 700 metres a year, but the population can spread much farther and faster when it piggybacks on logs, wood chips and firewood being transported by people.

The emerald ash borer is native to China and eastern Asia.