Emerald ash borer leaves no leaf unturned


By Rhonda Massad

As yet another city, Beaconsfield,  finds itself with the emerald ash borer on its territory the fight to stop the green pest from destroying tree canopies across the country is not looking up.

As part of Laval’s strategy to combat the current ash tree crisis, a public information session on the emerald ash borer (EAB) was held on April 23, at Pavillon du Boisé Papineau on Saint Martin. The room capacity was no where near full with less than ten audience members.  There were no elected officials present.

Laval’s territory covers 246 square kilometres with a population of 421,500 residents and 10,000 ash trees both public and private. Out of 66 EAB traps placed throughout the city in 2014, 34 traps were positive for the EAB and 37 public treeswere infested. Eight areas of infestation were also found.

Three panelists were present to inform the public of the current ash tree crisis plaguing Laval’s tree canopy, Canadian Forest Services Pierre Desrochers, UQAM’s Forestry department Alain Paquette and Laval’s Green space division Forestry engineer Daniel Boyer provided information on the short and long term approach to saving Laval’s tree canopy.

Major concerns expressed by all three panelists was the destruction of the city’s tree canopy.  Canopy loss impacts residents in many ways, worsening of urban heat islands, landscape degradation and the impact on citizen’s health.  According to panelist Alain Paquette, the tree canopy reduces air pollution which increases life expectancy.

According to Daniel Boyer, though the eradication of the EAB is impossible, the city has adopted the Slow Ash Mortality (SLAM) approach to managing the crisis. Treatment with TreeAzin and felling of trees will be combined with a diverse species replacement plan.

TreeAzin is a class four bio pesticide, derived from the Neem tree, that is injected into the bark of the tree.  The treatment must take place every two years for the life of the tree.

TreeAzin has risks as do all pesticides. We want manage the mortality of the ash trees and it is our hope that we are not treating with TreeAzin in ten years from now,” Boyer stated, “our intention is to gradually replace the trees with a variety of species to avoid any future incidents like this.”

According to Boyer there is a residue of TreeAzin remaining in the leaves that fall to the ground. TreeAzin should not be injected in ash trees that line bodies of water as it will impact the eco systems within the water and on the shore line.

Pierre Durocher was hopeful that a method of auto contamination by the spread of a fungus to the EAB will become prominent shortly.  When the EAB enters a Lindgren trap designed to attract the EAB, it becomes infected with fungus spores that it carries back into nature and produces eggs infected with the fungus.  Montreal will be using this method this summer in their efforts to ward off the EAB.

Research is being conducted on a parasite that feeds only off the EAB that also holds promising reports. The insidious emerald ash borer likely arrived in North America from Asia in the early 1990s on shipping palettes, but was only discovered in North America in 2002, first discovered in Laval in 2012.  The female insect can only travel around 1 kilometre on it’s own, the rapid dispersal over long distances is attributable to the transport of firewood.  Since its arrival in North America, the EAB have destroyed millions of ash trees and continues to spread.

The full power point presentation along with more information on what to do if you have an infected ash tree is available at http://www.credelaval.qc.ca


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