More than 200,000 ash trees in Montreal are now at the mercy of a swarm of shiny green bugs.

The emerald ash borer, a type of beetle responsible for destroying the ash populations of certain spots in Quebec and Ontario, has been in North America for just over a decade.

Robert Lavallée, a pest management research scientist for Natural Resources Canada, said one in five trees in Montreal is ash — that adds up to 200,000 trees, not including the ones on private property and on Mount-Royal.

Native to Asia and east Russia, the emerald ash borer made its first Canadian appearance in Ontario in 2002. The insect has been causing serious problems in Quebec since it was discovered in Carignan, on Montreal’s south shore, in 2008.

Lavallée said that once the emerald ash borer has moved into an area, it’s almost impossible to eradicate. According to the Canadian Food Inspection Agency, the larvae destroys "the layer under the bark that’s responsible for transporting nutrients and water throughout the tree."

Once infested, an ash tree usually dies in two to five years.

In an effort to curb the bug’s presence in Montreal, Lavallée and his team have set up traps in several Montreal-area boroughs and municipalities: Rosemont, Côte-des-Neiges, St-Laurent, Ville-Marie, Pointe-Claire and St-Bruno.

"I selected those boroughs simply because there are ash," he said.

"We unfortunately found that the highest number of insects in our traps was in Côte-des-Neiges."

The public can help limit the damage, Lavallée said, by not moving any wood or firewood from one part of the city to another.

"People should respect the advertisement made by the city or CFIA saying do not move any wood from an infested area to a non infested, but basically, do not move any wood," he said.