Emerald Ash Borer
The emerald ash borer (also known as EAB) is a very destructive wood boring beetle which attacks and kills
all native species of ash trees.
EAB was first noted in North America in 2002 in Detroit, Michigan and shortly thereafter in Windsor, Ontario. The invasive beetle has since spread to other areas in Ontario, Quebec and the United States. Its presence has been confirmed in Ottawa as well as Prescott-Russell and Leeds and Grenville Counties.
At this time, there are no confirmed reports of emerald ash borer in Cornwall or the United Counties of Stormont, Dundas and Glengarry, however there is a strong likelihood that it will eventually appear in the area.
EAB does not pose a risk to human health.
The City of Cornwall has begun to prepare for the arrival of the emerald ash borer in the community. Parks and Recreation staff is monitoring the situation closely while also working to raise awareness about the threat posed by this invasive species.
Here are some answers to commonly-asked questions regarding the emerald ash borer:
What does the emerald ash borer look like?
The beetle is green in colour and measures about
3 to 3.5 millimetres wide by 8 to 15 millimetres long.
When present adults might be seen on or near ash trees from early June to the end of August. The adults feed along the margins of ash leaves, they mate, and then the females deposit their eggs in bark crevices or under bark scales.
What tree species are susceptible to attack by the emerald ash borer?
The emerald ash borer has been found to attack and kill all North American species of ash (Fraxinus). The larvae feeds on the cambium layer under the bark which carries water and nutrients.
Infested ash trees typically die two to three years after initial damage is noted.
How important are ash trees?
Ash trees are an important part of Canada's urban and rural landscape. In Cornwall, it's estimated that native ash trees account for 25 to 30 % of all trees within the City.
Like all trees, ash trees help to increase shading and water retention, thereby reducing air conditioning costs and
sewage treatment costs. They also help to improve air quality.
How is the emerald ash borer spread?
The most common way for the emerald ash borer to spread is through people moving infested materials such as firewood.
Scientists in Canada and the United States have concluded that the emerald ash borer cannot be eradicated. In light of this the Canadian Food Inspection Agency (CFIA) adopted a "slow-the-spread" approach.
To help limit the spread, ministerial orders have been put in place to regulate areas infested by the pest.
The CFIA is the federal governing body responsible for exotic insects.
What should I do if I have an ash tree on my property?
Property owners are responsible for the care of privately-owned trees. The City of Cornwall recommends you monitor the condition of your tree and look for signs of infestation.
Some signs of infestation include:
- Presence of woodpeckers in winter and woodpecker holes
- Thinning crown / dying branches
- Reduced foliage density
- Shoots growing from the trunK or branches
- Deformed bark areas
- Vertical cracks on the trunk
- Small D-shaped emergence holes
- S-shaped tunnels under the bark filled with fine sawdust
- Evidence of adult feeding on leaves (beginning in late May)
If you see signs that your ash tree is dead or dying, you should contact a professional tree care company.
Also, if you have found a beetle or damage that you suspect is emerald ash borer, contact the Canadian Food Inspection Agency. The CFIA has established an Emerald Ash Borer Hotline which can be reached at 1-866-463-6017.
Residents who suspect EAB damage are also asked to call the City's Parks and Landscaping office at (613) 930-2787 ext. 2261.
If an emerald ash borer infestation is detected early, you may consider asking your tree care company to assess whether the tree may benefit from TreeAzin injections.
What is TreeAzin?
At present, TreeAzin is the only product registered for use in Canada against EAB. IT has been shown to be effective in the control of EAB.
Is the City of Cornwall planning to use TreeAzin to treat ash trees?
At present, City staff along with a working sub-group of the Municipal Environmental Advisory Committee is assessing all aspects of EAB control.
What will happen to the City-owned ash tree on or near my property?
City staff require your assistance to monitor the health of City trees in your neighbourhood. If a City tree appears to be in decline, please advise the Parks and Landscaping Section at (613) 930-2787 ext. 2261. The tree will be assessed by a certified arborist and appropriate best arboricultural practices will be applied to maintain the urban forest.
You can find out more about the emerald ash borer through the following resources: