CFIA attempts to slow spread of emerald ash borer.

Despite removing and destroying all ash trees in a 10-km wide by 30-km long piece of land from Lake St. Clair to Lake Erie, Canadian Food Inspection Agency (CFIA) surveyors continue to find trees infested with emerald ash borer (EAB) east of the Ash Free Zone.
According to Ken Marchant, forestry specialist with CFIA, “50,000 more ash trees were removed in Chatham-Kent county last spring. Of those trees, 81 were found to be infested with EAB. What’s troubling is that some of the trees were heavily infested, but showed no outward signs of infestation.” Evidence like this underlines the difficulty in early detection of the tiny pest.

CFIA continues to survey along the St. Clair River corridor, from Walpole Island north to Sarnia. Positive finds show EAB has blown across the St. Clair River from Michigan. In addition, Marchant says that one outlier has been found in Elgin County near Dutton. “Thanks to our previous research with infested sites, we know the pest has been in that area for five years,” explains Marchant. CFIA is working with the Canadian Forestry Service to study the outlier site. Because of its isolation, it is an ideal research site to learn more about the life cycle and behaviour of the EAB. Forestry experts say this is the worst forest pest they have come across.
The rest of Canada is beginning to take notice of the infestation in southwestern Ontario. “This is generating interest and concern across Canada,” says Marchant. “City officials in Winnipeg estimate there are 300,000 ash trees lining city streets. To lose this many trees would be devastating.”

Scientists in both Canada and the U.S. admit this pest will never be eradicated. “The best we can do is slow its spread.” Pesticides are being registered that will help control EAB, but as Marchant explains, “ash is so widespread across this continent that it would be too expensive and time-consuming to treat every tree at risk of infection. Pesticides, once registered for use, will be a tool to slow the spread of EAB, not eradicate it.”

“The biggest limitation to controlling EAB is that we can’t find it at low levels of infestation. By the time the damage is noticed, we’ve missed the leading edge by 30 to 40 kilometres,” says Marchant.
For more information, or updates on EAB, visit www.inspection.gc.ca