Invasive beetle could wipe out most of HRM’s ash trees within a decade
Posted Dec 10, 2018 03:28:12 PM.
This article is more than 5 years old.
It's likely the majority of ash trees in the Halifax area will be lost within the next decade.
That's according to Halifax Regional Municipality's superintendent of urban forestry, Crispin Wood.
In September, an invasive, tree-destroying beetle was discovered in Bedford's DeWolf Park. Since then, Wood said the emerald ash borer has killed three trees in that area.
“Which isn't significant, but the park has a fairly large population of ash, which are all well within the sights now of the beetle,” he explained.
The park is in the early stages of an infestation, which can spread quickly.
According Natural Resources Canada, it typically takes just six years after an infestation arrives in a woodlot to kill more than 99 per cent of the ash trees.
Wood said it's the larvae that do the damage. They chew the live tissue, cutting off the flow of sap and water up and down the tree, eventually destroying the ash.
“One beetle larvae can actually do a fair amount of damage. On a mature tree, if you end up with 20 larvae, and numbers could exceed thousands, very quickly a tree can be killed,” Wood said.
“And then of course, when those larvae, after a year or two of chewing, emerge as adult beetles, they'll mate, lay eggs on an adjacent tree and the cycle continues. It just keeps spreading from tree to tree to tree.”
Emerald ash borer is originally from Asia and arrived in Canada in 2002. It was reported in the Detroit area and quickly spread across the border to Windsor, then through Southern Ontario.
It's not known exactly how the invasive species made its way to DeWolf Park, but Wood said there's several ways it could have travelled there.
“We do know that they fly, they can hitch a ride on vehicles, they can be moved by firewood, they can be moved by nursery stock … they can come by boat inside shipping containers.”
Wood said there are treatment options to slow it down, but not to stop the spread of emerald ash borer.
“Obviously we will look at removing affected trees to get as many as the beetle larvae and potential beetles out of the area as quickly as possible,” he said.
As far as other methods, Wood said the department is working on a management plan which they hope to have in place by spring.
