First spotted in city trees last year, the tree lice was considered low risk at the time. But with a year's worth of surveying, Barwinsky said about 700 black ash trees — the preferred host of the insect — are now dead or in severe decline. "We know it's in other neighbourhoods … but it just reinforces the fact that [the emerald ash borer] is a difficult pest to detect," she said. The city's receding tree canopy: every removed tree between 2013 and 2017Each dot on the map represents a tree that was removed between 2013 and 2017. (CBC News) Homeowners can help alleviate the stress trees are under by ensuring they are kept well-hydrated during droughts, Barwinsky said.

Source: CBC News September 18, 2018 10:07 UTC