TO THE RESCUE OF THE ASH TREE
Emerald ash borer discovered last July
ASH BORER THREAT Public works employee Marc-André Moise installs an emerald ash borer bait trap in Beaconsfield, where the insect has not yet been found. Monique Beaudin reports that Montreal – where about one in five publicly owned trees is an ash – will spend $2 million to try to slow the insect’s spread. Without action, the island’s ash trees could be lost within 10 to 15 years.
The emerald ash borer flies on. The iridescent green beetle native to Asia has been sweeping across eastern North America for 10 years, wiping out ash trees along the way.
First seen in Montreal last July, the small green insects had destroyed 15 trees by April. Since then, at least seven other damaged trees have been found.
Cities and towns are trying to slow the insect’s progression to protect the estimated 195,000 ash trees in parks and along city streets. The city of Montreal says one in five publicly owned trees in Montreal is an ash.
Adult ash borers feed on the leaves of ash trees and lay their eggs on the bark. Their larvae tunnel small holes into the bark, and feed on the tree beneath, creating S-shaped grooves in the wood. That prevents the tree from getting nutrients, and it dies. It can take as little as a year for the beetle to kill a healthy ash tree. Much of the damage is done under the bark.
“It’s not easy to detect the presence of the insect until the tree is very, very, very badly damaged,” Montreal spokesperson Valérie de Gagné said Tuesday.
The spread of the insect, which was first seen in Canada in 2002, is linked to human activity, through transportation of things such as young trees from nurseries, firewood, including to campgrounds, and wooden pallets used for transporting merchandise, according to the Canadian Food Inspection Agency. Scientists in Canada and the United States have concluded there is no way to eradicate the ash borer, the CFIA says.
The first sign of the insects in Montreal came last July, with the discovery of an ash borer in the Mercier-hochelaga-maisonneuve borough, near the Port of Montreal. While no one knows for sure how it got onto the island, there is a possibility it came on a wooden pallet through the port, de Gagné said.
Fifteen infested trees were cut down in Mercier-hochelaga-maisonneuve, Ahuntsic, Rosemont and St. Laurent. Since April, three damaged trees were found in Ahuntsic and four in Hampstead.
“Unfortunately, that probably means there are much more, but four is what we were able to detect at this stage,” said Hampstead town clerk Andrew Ross, adding the trees have been cut down.
Between now and 2015, Montreal will spend $2 million to try to slow the spread of the insect by injecting trees with a pesticide, cutting down damaged trees and encouraging residents to separate branches from other yard waste for green-waste collections. Without action, Montreal says the island’s ash trees could be lost within the next 10 to 15 years.
City workers are injecting the pesticide into 700 trees this summer to kill the ash borer larvae. It will be used on ash trees in a 250-metre radius of trees that have been damaged or cut down, de Gagné said.
In April, the CFIA issued an order preventing ash trees from being removed from Montreal Island without permission. That affected green-waste pickups during the spring, and citizens were asked to set tree branches aside from their regular green yard waste and to call 311 information lines to have municipal workers collect the branches. Those restrictions on putting out branches will continue for fall green-waste pickups, de Gagné added.
In Beaconsfield, where there are about 1,400 publicly owned ash trees, a team of forestry engineers is inspecting the trees for signs of the ash borer, said Kovalski Lachance of Beaconsfield’s public works department.
There are even more ash trees on private property, and Beaconsfield has put up signs and added information to its website to alert citizens to the ash borers and their effect on trees, Lachance said. In the past week, the city has also put up traps to see if the insect is in the city.
In some cities in Ontario and the United States, where ash trees were completely wiped out. Montreal-area municipalities have been able to take steps to try to prevent the spread of the beetle thanks to early detection, he said.
“Here in the region of Montreal we are lucky because there are just a few infestation sites with one or two trees each; it hasn’t infested a forest,” he said. “So far we haven’t discovered a single ash borer in Beaconsfield.”