Ash Borer invasion: The Emerald Ash Borer is destroying trees in four southwestern Ontario counties. And experts say the pest is heading this way

The Expositor (Brantford)| Wed 15 Mar 2006 | Page: C1 / Front | Section: Crossroads
Byline: John Paul Zronik | Dateline: BRANTFORD | Source: The Expositor

BRANTFORD - Just to the west, millions and millions of destructive Asian insects are laying waste thousands of ash trees in four counties.

And the pests, known as Emerald Ash Borers, are heading this way.

"I have no doubts it will continue to spread east," says Jerry Dowding, Emerald Ash Borer project manager with the Canadian Food Inspection Agency. "It's an invasive insect. There are no known predators in North America."

Adult ash borers are long, slender and metallic green in colour, measuring between 8.5 and 13.5 millimetres. For their size, the insects do a lot of damage, killing infested trees in just two to three years.

Since its arrival in Canada, first documented in 2002, the Emerald Ash Borer has only shown an appetite for ash trees. According to Natural Resources Canada's Web site, more than one billion ash trees in the province could be threatened. In the U.S. and Canada, damage caused by the insect is estimated to be in the tens of millions of dollars.

It is thought the insects made their way to North America in wooden shipping crates while still in the larval stage via airplane or ship.

Essex County and Chatham-Kent are both under full quarantine because of ash borer infestation. Parts of both Elgin and Lambton counties are under partial quarantine, with full quarantines pending because of the bug's spread.

The quarantine means the movement of ash trees, including logs, firewood, lumber, wood chips, bark chips and other wood debris, out of infested municipalities is prohibited.

"We're talking hundreds of millions (of ash borers) in Essex County alone," Dowding says. "It's a primary tree killer, which means it attacks and kills healthy trees.

"We're finding it right up to Thamesville now."

Willfully violating the quarantine can result in fines of up to $250,000 or two years in jail.

CREEPY

As it creeps eastward, the insect moves closer to taking up residence in this area. Elgin County, already under partial quarantine, borders on Norfolk and is just one county removed from Brant.

Dowding said the ash borer could make its way to Brant County soon, but it could take years to get here.

"It could happen tomorrow, it could happen next week," Dowding says. "If someone moves infested firewood or logs, it could be on your doorstep tomorrow. If allowed to spread naturally, it could be years before it reaches Brant County."

Dowding says the movement of firewood played a big part in the bug's spread through Essex County. In firewood, the bug can fully develop and be transported over great distances. Researchers speculate its natural range to be one to two kilometres.

The Canadian Food Inspection Agency is charged with preventing the further spread of the insect in southwestern Ontario.

Dowding says the ash borer first appeared in Detroit, possibly between 10 and 15 years ago, near the city's airport. But it wasn't until 2002 that people realized what was killing ash trees in the area.

"Prior to that, no one took the time to investigate why all these trees were dying," Dowding says. "Up until (2002) people assumed it was a disease or drought.

"When we first found it, we knew nothing about it."

Two ash borers must have made it to adulthood in North America after a journey from Asia, as it takes two of the bugs to reproduce.

When it was discovered that a previously unknown metallic green insect was killing the ash trees, samples of the bug were sent around the world in hopes of identifying it. The insect's origins in Asia were eventually discovered, but it had no common name. A Michigan researcher dubbed it the Emerald Ash Borer.

Since 2002, the insect has spread into Windsor and on to other municipalities in southwestern Ontario.

Is the spread of the menacing insect under control?

"Definitely not," Dowding says. "What we're trying to do is slow the spread of this insect. We recognized from the outset that there was no way of stopping it."

A single infested ash tree can contain up to 10,000 insects, Dowding said. Not even cutting down ash trees in areas where the bug has been found would be enough to stop its spread.

In Canada and the U.S., governments and organizations are working to combat the spread, including the Canadian Forest Service, the Ministry of Natural Resources, the U.S. Department of Agriculture and universities.

The Emerald Ash Borer has caused its share of problems south of the border as well, killing between eight and 10 million ash trees in U.S. states including Michigan, Ohio and Indiana.

"It's difficult to describe the spread because what we're finding out is that the insect is near impossible to identify in small numbers," Dowding says.

The ash borer can be in an area three to four years before people begin to realize that there's a problem.

As the insect spreads, Dowding says there's a chance a natural predator will find the ash borer a suitable source of food. He says a type of native wasp and woodpecker are showing interest in eating the pests. In Asia, natural predators keep the Ash Borer in check.

During winter months, the ash borers remain inside trees. This time of year, larva can be found five or six millimeters into the wood. Having gone through its larval stages, the grown Emerald Ash Borer emerges from the inside of trees in late May or early June. They then begin feeding on the leaves of ash trees. The adult leaves a D-shaped hole after exiting a tree.

Other native insects can kill ash trees, but not as fast as the ash borer. They also don't leave the characteristic D-shaped hole, but an oval or round one.

Adult Emerald Ash Borers only eat the foliage on ash trees, causing minimal damage. But in the larvae stage, the insect is devastating, feeding on the inner bark of trees and interrupting their ability to send nutrients and water to all parts of the tree.

Scott Porter, Brantford's urban forestry co-ordinator, says the city's parks and recreation department has taken a proactive approach in anticipation of the Emerald Ash Borer's arrival here.

"It's not a matter of if, it's a matter of when this thing spreads," Porter says. "It just takes one piece of wood with a male and female in it for it to spread.

"If it does come... there's not really much you can do."

Porter says the city has just over 4,200 ash trees, not including those on woodlots or private property.

To alert residents of the ash borer's potential arrival, the city last year distributed flyers in hydro bills. It has also published information about the insect in its civic news publications and leisure activity guide.

The city employs two foresters. They, along with workers doing maintenance on city trees, are keeping an eye out for signs of the ash borer. Porter says the city is keeping the lines of communication open with Brant County, Six Nations and the Grand River Conservation Authority when it comes to the bug. Ash trees have also been taken off the city's planting list.

Clayton Thompson, Brant County's forestry officer, said he hasn't seen any signs of ash borer infestation in the county.

"It isn't in our area and probably won't be for some time if it comes at all," he says.

Thompson says some county residents are keeping an eye out for the ash borer. He recently responded to a call from a resident concerned they discovered an Emerald Ash Borer, but the insect turned out to be a millipede.

"It's always a good idea to keep an eye out for it, but its not here yet," Thompson says.

If the insect were to invade Brant, Thompson says the impact could be as devastating as in areas where it has taken up residence.

"It would probably be just as bad here as it would anywhere else," Thompson says. "We do have some young stands of ash in Brant, so they could affect those.

"But I don't expect to see one and I hope I don't."

Dowding said it's a good idea for everyone to keep an eye out for the bug.

"Everyone right across southern Ontario should be looking out for it," he says.

If people find evidence of an Emerald Ash Borer, Dowding says they should call 866-463-6017.