Emerald ash borer: how a tiny bug could cost big bucks

The emerald ash borer could cost the Grand River Conservation Authority between $4 to $8 million over the next decade, according to the authority's chief forester.

Invasive pest could cost $8 million over 10 years, Grand River Conservation Authority says

The emerald ash borer could cost the Grand River Conservation Authority between anywhere $4 to $8 million over the next decade and result in the destruction of tens of thousands of ash trees, according to the authority's top forester.

Originally native to Asia, the emerald ash borer was first detected in Detroit in 2002 and since then has been slowly spread across North America decimating the native ash tree population. 

The insects has no native predators in North America and once the emerald ash borer lays its eggs, the larvae slowly kill off their host tree, feeding off of the inner parts of the plant and thereby cutting off the tree's access to water and nutrients.

It's a fate that GRCA forester Ron Wu-Winter estimates will befall tens of thousands of ash trees across the Grand River watershed over the next decade as the insect continues its relentless spread. 

According to Wu-Winter, the situation is exacerbated by the fact that dead or dying ash trees become a safety hazard because the insect infestation weakens them to the point that they risk toppling onto property or people. 

"So these are trees that are either over a roadway, or campsites or our trail systems and as they die, we're going to have to remove those trees, or at least the majority of trees and that is going to be, for us the greatest expense," said Wu-Winter.

That expense could range as high as $8 million dollars for the removal of dead or dying ash trees over the next 10 years according to Wu-Winter, who noted the cost will more likely be half of that. 

"What we found was within our gated parks, we're looking upwards of possibly $4 million over the next ten years to deal with dead and declining ash trees," said Wu-Winter. "That's simply our 11 gated parks and primarily areas like campgrounds, the road systems in those parks and the trail systems." 

Wu-Winter says the GRCA may be able to reduce that cost somewhat through cost savings, but just to maintain inside the parks he thinks will cost between $2.5 - $4 million. 

According to Wu-Winter, $150,000 has been allocated for 2014 to cut down the hazard trees, and a further $400,000 for 2015, though that figure is pending budget approval. 

"Beyond our gated parks we have nearly 200 kilometres of trails on our other properties. If we were to remove ash trees across all those areas, that could be an additional cost of upwards of another $4 million dollars. But that would be the highest potential cost, removing all those trees with climbing arbourist crews," he says.

However, Wu-Winter says it may not be possible to even get to all of those trees, and that the GRCA would try to find the most cost-effective way to remove the ash trees. 

"We are just starting to proactively cut ash trees that are dead and declining. This fall we may remove, I would guess 300,400 trees from two of our parks," said Wu-Winter, who specified the cutting had started in October. 

"Over the next two or three years I think people are really going to notice along the streets and along forest edges, dead and dying trees and those will primarily be ash."