Tiny pest a big problem

They may be less than one centimetre long, but the City of Stratford knows better than to mess with the Emerald Ash Borer.
That’s why it is taking preventative measures against the invasive beetle that has already destroyed millions of trees in Michigan and Ontario.
Last Friday, Strathroy-based Arbortech Professional Tree Care began injecting select trees with TreeAzin, a systemic insecticide designed to exterminate the destructive pests before they have a chance to kill a tree.
There’s no evidence the Emerald Ash Borer has made its way to Stratford yet, but with major infestations in Huron and Middlesex counties, it’s only a matter of time.
“They haven’t confirmed we have anything here in Stratford, but we are surrounded by it,” said Quin Malott, parks and forestry manager. “We want to get going on this product and save some of these high-value, quality park trees for now.”
The first round of treatments will cost about $10,000, and will be administered to about 55 ash trees in the main parks system.
In total, there are about 135 susceptible trees in the park system and between 1,600 to 1,800 across the city. Eight per cent of the city’s trees are ash, not counting those in parks, ravines and natural areas.
Because of the devastating effects of the beetle in other areas, ash trees haven’t been planted locally since 2006.
Additionally, the city has moved away from monoculture – planting only one species of tree – to a more encompassing program that sees up to 20 different varieties planted.
However, there are pockets of the city with plenty of ash trees, since they were the planting of choice in the 1970s. Those areas will likely be wiped out once the Emerald Ash Borer arrives.
“Logistically, it’s probably not feasible to do every tree because this product has to be reinjected once every two to three years,” said Malott, explaining it is an expensive treatment.
“But if you lose some of these large trees, it will be generations before they come back, especially in these park settings.”
Earlier this year, the city opted to reduce the number of new trees planted and use some of the budgeted money for the TreeAzin program.
There is also an Emerald Ash Borer reserve fund that is accumulating money for future treatments.
Though TreeAzin is a good treatment – it’s even shown ability to save trees with 40 per cent infestation rates – it’s not a cure-all. Malott expects when the borer arrives in Stratford, only between five to 10 per cent of ash trees will be saved, mostly due to budget restraints.
While all trees cannot be inoculated, it is money well spent for the ones that are, he said.
“If you don’t do anything, you’re going to lose them,” Malott said. “So we’re going to try something to save them.”
Ian Johnston, arborist and owner of Arbortech Professional Tree Care, said TreeAzin has been used with great success in other municipalities.
In Oakville – where an aggressive program to treat 1,600 trees is under way – they’ve seen results. Trees treated in the immediate vicinity of City Hall back in 2008 are “beautiful,” while others on the perimeter that did not receive TreeAzin have been destroyed by the Emerald Ash Borer and are being removed, Johnston said.
To administer TreeAzin, small holes are drilled in the trunk of the tree and vials of the insecticide are administered. The tree brings up the solution through its vascular tissues.
The adult beetles ingest the TreeAzin – derived from seeds of the Indian neem tree and synthesized by a Burlington-based company – which makes them sterile and unable to reproduce.
Larvae that ingest it are unable to shed their skin as they grow, leading to death.
“They get too big for their britches and they die,” explained Johnston.
TreeAzin is classified as a pesticide, but has received emergency registration from the province to allow it to be professionally applied.
It poses no threat to humans or animals because it is contained within the tree, Johnston said.
He’s seen the destruction in other communities, like Windsor, which was hit hard before TreeAzin was discovered as a way to fight infestations. The borer first came to Windsor seven to eight years ago and the municipality is still cutting trees down.
“They’ve lost thousands and thousands of trees,” Johnston said.
So what’s being done to monitor the local situation and how will authorities know when the Emerald Ash Borer finally arrives?
That is being handled by the Canadian Food Inspection Agency (CFIA), said Malott. Twelve traps have been set up around the perimeter of the city and in the parks system and are monitored by the CFIA.
“At this point they haven’t told me they’ve found anything,” Malott said.
Often, the Emerald Ash Borer is moved by humans, usually through transport of firewood from one area to another. Because there aren’t campgrounds within the city limits, Malott guesses that is the reason the borer has been slow to arrive.
“But it does move naturally, it can fly and move on,” he warned.
It is expected the first round of inoculations could take up to two weeks to be completed.

Republished from Tori Sutton article in Stratford Gazette August 5, 2010

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