City of Ottawa is now using TreeAzin "Off Label". Injections every year. At a major risk to tree health due to injection site wounding. As well as extreme costs associated with product.
TreeAzin® Systemic Insecticide is owned by the Canadian Forest Service and was developed in collaboration with BioForest, who holds its worldwide license. TreeAzin is distributed by BioForest in Canada and by Rainbow Treecare Scientific Advancements in the U.S.
Emerald ash borer fight moves west
By David Reevely, Ottawa Citizen
OTTAWA — The way Ottawa is slowly losing the fight against emerald ash borers is a lot more visible to a lot more people now that the bugs have moved into downtown.
Ash borers were detected in this city in 2008 and they typically kill a tree in about five years, starting from the top, as their larvae chew through the wood under the bark. They were first confirmed in trees southeast of downtown and have been emanating in all directions since. Ashes are about a quarter of Ottawa’s trees, so when they go, people notice.
“Now you’re into Greenboro, downtown. It’s not as noticeable as you come west toward Woodroffe; it’s more pockets,” says David Barkley, the city government’s chief forester. “The population’s growing. That’s one of the things you can definitely notice more this year than in some others, you can see insects on the trees and on the green growth at the bottom that’s sprouting out.”
Those shoots are one of the last gasps of a tree that’s too infested to survive. Especially downtown, Barkley says, the city’s finding that the pesticide it’s injected into some ashes it considers especially important (because they’re especially large and beautiful or because a whole stand of threatened ash trees provides shade for a playground, for instance) isn’t working. Instead of injections every two years, the city’s moved back to applying the chemicals annually, because many trees it treated have died anyway. Even half a dozen ashes shading the playground of City Hall’s daycare are dead or dying, despite the telltale metal tags hammered into their trunks showing they’ve been treated.
“We don’t know if it’s condition, where the tree is growing, the population,” Barkley says.
He means the population of bugs might be greater than expected and some trees might just be weaker than his experts thought and less able to resist the ash borers even with chemical help — particularly after last year’s summer drought. Downtown especially, growing conditions can be tough for trees anyway, with their roots covered over with concrete, salt spray in the winter and extra heat reflecting off nearby buildings in the summer.
Outside downtown, though, many ash trees aren’t good candidates for the TreeAzin pesticide treatment because they aren’t big enough. People may notice more dead trees because it’s been a bad season for Dutch elm disease, too, Barkley says.
The city’s spending $1.8 million on the ash borer fight this year, on injections, cutting down infested trees and experiments with other governments. The federal government has approved the release of non-native wasps that feed on the borers in China; Barkley hopes that’ll help especially in suburban woodlots. But they’ll need a lot of ash borers to eat if they’re going to sustain themselves, meaning they’re more likely to cap the borer population at a pretty high level than to knock it down.
Barkley compares this fight to a slow-motion version of the 1998 ice storm in the damage it’s doing. The pesticides and the wasps will only ever slow the ash borers down, giving time for new trees to grow and replace them. Alta Vista Drive, which is completely lined with ash trees, has been an early target for both the ash borers and the city’s attacks, with numerous small trees planted along its boulevards next to dying ashes. It’s bad there, but not as bad as Barkley feared it would be.
“We’ve been doing a lot of planting. This year we’re looking at planting about 5,700 trees and we’ll probably remove less than half that. If we can keep this pace the next few years — we’re in the rural villages now, planting and filling in — if we can keep ahead of it, I think the residents will see that we’re not changing the look that much,” Barkley says. “We’re doing something. So when I look at some of the streets that we can do planting on, we’re mixing up the diversity so we won’t go through this again.”