Emerald ash borer beetle surveys begin at 'ground zero' infestation site in Winnipeg

Citycrews teamed up with national pest scientists this week to diagnosethe extent of Winnipeg's emerald ash borer beetle invasion, a budding issue that could end up costing taxpayers hundreds of millions of dollars.

The first confirmed case of emerald ash borer beetles in Manitoba was confirmed in a boulevard tree on Cote Street, in Winnipeg's St. Boniface neighbourhood, in November.

Colin Desrochersand Richard Featherstonlivein the leafy neighbourhood. Neither werethrilled to know the area could lose its ash trees.

"Having the trees with the canopies it's just fantastic here, so hearing about the beetles, it's devastating," said Desrochers.

"The trees are part of the charm of St. Boniface," said Featherston.

"That's why we bought in this neighbourhood, so a little disappointed that we may lose a lot of our trees."

Pest biologists with the Canadian Food Inspection Agency arrivedin Winnipeg this week to help guide forestry crews through the first phase of diagnosing the problem.

TheCFIAmonitors pest invasions and regulates efforts to curb the spread of borers. As per its protocol, the first step for a municipality after an invasion is confirmed is to do ground surveys.

Those startedat "ground zero" on Cote StreetTuesday, city forester MarthaBarwinskysaid.

Telltale signs

A team of about 30 workers from the city's forestry branch began surveys on foot Tuesday.They started at the site of that first infected tree and fanned out in a one-kilometre radius, inspecting trees on public property for signs of the carving "galleries" left beneath the bark by borers.

On Wednesday, Barwinskyand the crews spread out to surrounding neighbourhoodsand conducted more surveys fromvehicles.

She says the team has already come across several other trees that look suspicious and may have broods of borers quietly gnawing away beneath the bark.

"It really is too soon to tell" how bad the spread is, Barwinsky said. "We think we found it in a few other trees."

Apart from direct signs of infection, surveyors are paying attention to high woodpecker activity in the area. Winnipeg is home to a handful of woodpecker species, and research in the U.S. has shown borers often end up on thebirds' menu.

Other indirect signals include "epicormic shoots" tiny new branches growing outfrom behind tree bark and D-shaped exit holes left behind by borer larvae.

350,000 trees at risk

Though its tiny size and shiny green carapace mightnot look intimidating, emerald ash borers have cost municipalities across North America billions of dollars since the insect was first detected here in Detroitand Windsor, Ont., in 2002.

Winnipeg has been preparing for an invasion for about a decade and was put on notice last year when the beetles popped up in Thunder Bay, Ont., less than 700 kilometres east of the city.

An estimated102,000 ash trees live in Winnipeg parks and on the city's boulevards. When you factor in all the benefitstheyconfer things like rainwater run-off prevention and the shade and beauty they provide the "value" of those trees is up around $437million, according to the city. A 2012 study estimated the cost of cutting down and replacing those trees at $200 million alone.

There are another250,000 ash trees on private property in the city.

Left unchecked, 99 per cent of the time a borer invasion virtually destroysan ash population in less than a decade, according to Natural Resources Canada.

'Serious matter for the city'

The first surveys in Winnipeg were expected to be done by Thursday. Experts from the Canadian Forest Service are flying to Winnipeg in January to help train city crewson more precise branch-sampling methods.

Barwinsky said she is hoping the beetle is involved in a two-year, rather than one-year, life cyclebecause thatwould increase the odds that the spread will move slower, and buy the city some time.

"How quickly it spreads and how long we're really going to be managing that first cycle, we don't know yet," she said.

"It's a serious matter for the city."

The forestry branch will submit a report to city council byFebruary that lays out a management plan and prices out how much control efforts will cost in 2018.

Canadian researchers experimented with the release of hundreds of parasitic wasps last year that take down borer larvae.Barwinskysaid it's too soon to say whether something like that will be implemented in Winnipeg.

The best thing homeowners can do to help prevent the spread is to report trees they believe are infested to the city andnot move any ash firewood they have stockpiled.

The 2,000 dots on the map below are a random sample of Winnipeg's green ash trees, the second-most common tree in the city. The data reveals although the tree was widely planted across the city, there are high concentrations in newer neighbourhoods, whichexperts say are likely to become the problem areas with the appearance of the emerald ash borerin Winnipeg.

View the map on mobile here.