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Emerald Ash Borer

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Emerald Ash Borer (EAB) is extremely invasive to our Ash tree population Emerald ash borer is a destructive wood boring insect that prefers all Ash tree species as it’s host to complete its life cycle. The emerald ash borer completes its most destructive period of its life cycle in its larval stage, between August and October of each year.  These larvae feed on the inner bark and sap wood of the host tree creating galleries in the main trunk and larger branches that prohibit movement of water and nutrients from the roots of the tree to the leaves. The adult borer is an emerald green-winged beetle that has the capability of moving rapidly across the landscape in its quest of finding new host trees within which to complete its life cycle.  Depending on the level of infestation, repeated life cycles of this insect will eventually kill the tree within a few years of initial infestation.

Emerald ash borer originates in China, Japan, Korea and several other far eastern countries. The insect was first detected in North America in the Eastern United States and has since migrated north into Canada.  The Canadian Food Inspection Agency (CFIA) is monitoring the advancement of this insect in the province and has recently expanded and amalgamated quarantine areas in response to the further spread and detection of this insect within the Province of Ontario and Quebec.  The emerald ash borer was discovered in Windsor, Ontario in 2002. More recently the insect has been confirmed in Toronto, Vaughan and Markham and was found in Richmond Hill in March of 2011, and most recently in northern York Region in 2012, among many other communities in Canada and the United States.

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East Gwillimbury Strategy

As a result of the infestation the Town formulated a cohesive planned approach to manage the effects of this predator and protect our natural heritage and in particular the Ash tree population in East Gwillimbury.  The Town will use best practices of other municipalities who have been fighting emerald ash borer infestation since 2002.

The Town has committed to a three phase process.

Phase One Public Awareness Campaign - Ongoing

The Town continues to use in-house resources to conduct public awareness on the impacts of the emerald ash borer. To learn about EAB and the Town's strategy you can watch for notices on the Town Page, or pick up fact brochures with more details at the Civic Centre. 

Phase Two – Park & Streetscape Tree Inventory - Completed as of 2013

A comprehensive tree inventory was completed in Fall 2013 by the Davey Resource Group, a company with extensive experience in municipal tree inventory. The inventory focused on counting, evaluating and mapping park and street trees - where the first and most direct impacts of ash tree loss will be initially felt.  Ash trees in open space and valley systems are assessed on a case by case basis. This comprehensive park and street tree inventory will assist the Town with managing our urban forest in the case similar scenarios in the future.


Phases Three - Management Plan

Deferral Treatment

Ash tree injections are being carried out in order to defer costs and space out removals over our five year plan.

Removal or Replacement

For street trees and most park trees, the most cost effective management tool is to remove infested trees and plant new trees of a different species in their place. Unfortunately, there are no effective or efficient measures available in controlling the spread of this insect or controlling the damage that the insect causes in our open spaces, and because of this, we are expecting to see significant mortality in our inventory of ash species both in open spaces, and in wood lots. For these areas, relying on natural regeneration for replacement is the generally accepted approach.

View the list of Ash trees scheduled for removal or treatment 

View the Town's Management Plan Report