By Rhonda Massad
In the early 1900’s there was the chestnut blight, an exotic pathogen that altered the hardwood forest forever. A few decades later Dutch elm disease, an exotic pathogen carried by the exotic bark beetle, terrorized majestic elms all across North America.
The emerald ash borer is making history as it wreaks havoc on ash trees across the country. Laval has 5000 public ash trees and claims the same amount in the private sector. It has already killed millions of ash trees in Ontario, Quebec and the United States, and poses a major economic and environmental threat to urban and forested areas of North America.
The period for action against the insidious insect is between October and April, when the insect is dormant. The Canadian Food Inspection Agency (CFIA) suggests moving the trees to an authorized disposal site during this period.
Some typical signs that an ash tree is infected with EAB is an increase in woodpecker activity, the tree canopy begins to die back in the upper third portion of the canopy and bark splitting.
To cut down a tree in most cities, a permit is required. The wood collection service is offered free by the City of Laval if the ash is contaminated, the whole must be accompanied by a proof provided by a contractor.
TreeAzin, a Class 4 pesticide determined by the Pesticide Management Regulatory Agency, is the most widely used product available in Canada, it is produced by the BioForest company from the extract of neem seeds a product of the neem tree.
TreeAzin is effective against a variety of insects that consume tree tissues, not only will EAB larvae be affected, other insects feeding on the treated tree.
“In my opinion the residue left behind from the injection of several hundred thousand trees in the Montreal region would not be significant to harm a human,” John Gasparetto, Business Development and Technical Specialist at Bio Forest explained, “testing has shown that to harm a human it would take up to two litres to cause any damage.”
According to Health Canada the toxicology database for NeemAzal Technical, the active ingredient in TreeAzin, did not undergo the usual amount of studies required for pesticide registration.
In the available studies it was determined that the health effects in animals given repeated oral doses of NeenAzal included effects on the blood, liver, thyroid and kidney. When given to pregnant animals there were irregular bone ossification as well as heart abnormalities. Effects were present in both mother and fetus.
Health Canada also states on it’s website that although the toxicology database was not complete before product registration, toxicology studies that were complete rendered the pesticide acceptable.
Felling a substantial portion of mature trees dramatically alters the appearance of neighborhoods and diminishes property values. Stormwater run-off increases. Shade decreases and air conditioners run longer.
In 2013, a study done for the U.S. government and published in the American Journal of Preventive Medicine established a correlation between the presence of the emerald ash borer and an increase in deaths attributable to cardiovascular and respiratory illnesses. On average, the researchers witnessed 23.5 more deaths per 100,000 residents after the borer passed through a given area.