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Emerald Ash Borer
The Emerald Ash Borer (EAB) is an insect that kills all species of Ash trees native to North America. The
Emerald Ash Borer has already infested and will continue to destroy many Ash trees in Ontario, Quebec and the
Northeastern United States.
As EAB can be found City wide, dead and dying ash trees have become a safety concern.
A quick reference fact sheet is available for download here.
What is the Emerald Ash Borer (EAB)?
The Emerald Ash
Borer (EAB) is a highly destructive invasive insect that attacks and kills all species of Ash trees native to North
America. EAB has been declared an invasive alien species by the Canadian Food Inspection Agency (CFIA) and must be
Introduced from Asia in the early 1990s, but not discovered in the Detroit and Windsor areas until 2002, it is
believed that the insect was brought to North America unintentionally in wooden packing crates. In 2008 the CFIA
confirmed the presence of EAB in Mississauga.
EAB has been confirmed across Ontario, up to and including
Algoma District and Sault Ste. Marie, and has been identified in a large portion of Quebec. A large section of
Ontario and Quebec is now under quarantine and the movement of Ash wood products outside of the regulated area is
How do I know if I have an ash tree?
If you are uncertain whether or not you have an ash tree, check out this online resource that describes which
characteristics are present in ash trees.
Signs of EAB Infestation
D-shaped exit holes or woodpecker damage Photo courtesy of
David Cappaert, Bugwood.org
S-shaped galleries under bark
Epicormic shoots Pennsylvania Department of Conservation
and Natural Resources - Forestry, Bugwood.org
What is the City doing?
In 2012, City Council approved the EAB Active
Management Plan, which began implementation in 2013. Now, five years into the 10 year plan, the City’s
Forestry Section has inspected City-owned ash trees to identify which trees are infested by EAB and must be removed
from City property and those who are sustainable and may be treated to prevent infestation. These include trees on
streets, in parks and in woodlots.
The City has inspected all city-owned Ash trees on streets and in parks and continues to inspect trees in
woodlots. City contracted crews have treated sustainable Ash trees on streets and in parks with TreeAzin™, a
product regulated in Canada for treating the impacts of EAB on Ash Trees. The treatment window is between June and
Staff are currently inspecting trees for treatment in 2018. Trees suitable for treatment will be marked with a blue dot.
Green prism traps are placed around the City to monitor the population levels of the EAB beetle. The
City has been using this type of trap since 2013 and puts them near ash trees every other year (2013, 2015, and
2017) near ash trees that have been treated with TreeAzin or in woodlots that have or had ash trees previously.
The traps are placed in May and remain up until the fall when the adult EAB beetles have finished flying for the
year. The traps use an odour that smells like stressed ash trees to attract EAB so that the beetle sticks to the
side of the trap when it flies into it. When the traps are taken down, the amount of adult beetles is counted. This
data is analyzed to create a population curve to track population changes of EAB in Mississauga.
All trees scheduled for removal have been marked with an orange X. Residents with a
street tree in front of or adjacent to their house that is scheduled for removal have been notified about the
upcoming work. After the initial tree removal, crews will return to remove the tree stumps, repair the ground with
topsoil and reseed.
City contracted crews will be removing street trees and trees in parks and woodlots all across Mississauga.
Removal will focus on high risk areas next to roadways, trails and paths, homes, schools and
For more information call 3-1-1 (905-615-4311 if outside city limits).
Replanting City-Owned Trees
All city-owned street and park trees removed due to EAB will be replanted within the community. Residential
streets are being replanted first, followed by arterial roads, industrial and commercial streets.
All street trees removed due to EAB will be replanted in the same place from which they are removed. However, in
some cases, it might not be possible to replant in the exact same location due to changes in overhead or
underground utility locations. In these cases, trees will be replanted in the surrounding neighbourhood. We will
advise residents of the change in location.
Trees will be replanted approximately one year after the stump is removed. The time may be affected due to the
short planting season and weather conditions.
Park trees will be replanted over several years. This is due to the high number of trees that were removed from
our parks, the short planting season and the weather conditions.
Forestry staff are currently working on individualized plans for replanting woodlots as each site is unique.
Work is prioritized based on woodlots with the most dead/dying trees. For some woodlots that experience only
minimal removals, it may mean letting these woodlots regenerate naturally while others will have trees
What Can You Do?
It is your responsibility to treat or remove dead or dying Ash trees on your
If a healthy Ash tree has been treated, it is recommended to continue to do so.
If an Ash tree has not been treated it is recommended that a Certified Arborist be called for advice.
Once infested with EAB, an Ash tree will die quickly. If your EAB infested ash tree is located in a yard, along
a street or a fence, it will pose a safety risk and should be removed.
Safety is the most important issue when determining when to remove your dead or dying ash tree.
How long has it been in the City?
EAB was first identified in Mississauga in 2008. Since that time Forestry staff has continuously monitored its
population growth and movement throughout the city.
How did it travel so quickly throughout southwestern Ontario?
EAB has spread rapidly due to the movement of infested firewood or ash tree nursery stock. All of southwestern
Ontario and parts of northern Ontario are under an imposed quarantine and the movement of any ash product outside
this area is prohibited. The regulated area, as defined by the CFIA, can be found here.
Where in the city is it located?
EAB is located within all Wards in the City.
How many ash trees are in Mississauga?
Mississauga's urban forest consists of approximately 2.1 million trees located on both public and private lands;
with approximately half (1 million) of which are privately owned. Ash species represent a significant component
(approximately 10%) of the tree canopy on both public and private land.
What types of tree does the EAB prefer?
It has only been found in Ash trees at this time. All species of Ash trees are susceptible. Forestry staff
continues to monitor research to see if EAB spreads to other tree species.
How big a problem is EAB in Mississauga?
EAB is one of the most destructive forest pests Mississauga has had to deal with. Of the City's 2.1 million trees,
it is estimated that 10% are Ash trees. This includes both public and private trees. The City implemented the EAB
Active Management Plan in an effort save some Ash trees and replant trees to offset the loss of trees.
What is the Active Management Plan and why did the City implement this plan?
In 2012, City Council approved the EAB Active Management Plan. Through this plan, the City will treat viable Ash
trees and remove and replace dead or dying city-owned ash trees. Read the plan here: Active Management Plan.
How much does the EAB Active Management Plan cost?
The EAB Active Management Plan will cost an estimated $51 million over nine to ten years based on available
treatment options. This includes, but is not limited to: the cost to treat trees that meet the City's established
criteria, remove dead or dying infested ash trees and replant street and park trees.
How is the City funding the EAB Active Management Plan?
Currently, neither the federal or provincial government is providing funding support for EAB. To support the EAB
Active Management Plan, the City implemented a Special Purpose Levy. The money collected is held in reserve for
this plan and funds are withdrawn each year based on the work to be completed.
Why has the City implemented a tax levy?
The EAB is an unplanned expense and the City does not have funding in place to treat viable Ash trees and remove
and replace dead or dying city-owned Ash trees. In order to pay for the implementation of the EAB Active
Management Plan, the cost has been passed on to the residents as a tax levy. By defraying the level over nine to
ten years, the impact to homeowners is minimized and some of our City-owned Ash trees can be preserved while
removing hazardous trees and replanting to restore our City's tree canopy.
What is the treatment criteria?
Based on best practices, Ash trees with no obvious signs of EAB infestation receive treatment. Some signs of EAB
infestation include dead/dying crown, bark cracks and EAB exit holes.
When are trees treated?
Trees were treated in 2014 and 2016 because the TreeAzin™ treatment is effective for 2 years. The next
treatment year is 2018. Before treatment occurs, trees are examined using the above criteria. Forestry staff
inspects all treated Ash trees annually to confirm if the treatment is working.
Will the City be treating trees on private property?
Private property owners and residents are responsible for all costs associated with the treatment or removal of ash
trees located on their property. The City will not treat privately-owned ash trees or provide financial or staff
resources to remove dead or declining ash trees on private property.
What product is the City using to protect its trees?
The City of Mississauga will use a Canadian-made product called TreeAzin™. TreeAzin™ is a biological
insecticide, made from a natural product from the extract of neem trees, developed by the Canadian
Forest Service and BioForest Technologies.
Can I purchase TreeAzin™ to protect trees on my property?
TreeAzin™ can only be administered by certified professionals. Please contact a certified arborist for more
details on the product and visit BioForest Technologies for a list of certified applicators.
How does the City determine when to remove an Ash tree?
Forestry staff has inventoried all city-owned Ash trees on streets and in Parks. The City continues to inspect all
woodlots. Safety is the most important issue when determining when to remove an Ash tree. Dead or dying Ash trees
located along trails, backyards or a fence will pose a safety risk and should be removed.
What is the plan for replanting trees?
All City-owned trees on streets and in parks will be replanted within the community. The goal is to replant trees
approximately 1 year after the stump has been removed. This will depend on how quickly EAB spreads and how quickly
we need to remove trees. Replanting is limited by a short planting season, and is the weather.
Do I have to call and report a street tree in front of or adjacent to my house that has been removed?
Forestry staff has inventoried all city-owned Ash trees on streets and in Parks. The City continues to inspect all
woodlots. We have a record of all Ash trees that have been removed and we will be replanting those trees. You will
receive a notice from the Forestry Section when your street tree is to be replanted.
What kind of trees will be replanted on streets and in parks?
The City no longer plants Ash trees. Forestry will carefully choose the type of tree to be planted based on the
tree's function, the intended location and soil conditions. The tree may need to be replanted in another location
in the community due to changes in underground utilities. Residents will be informed of these relocations.
Will the City remove ash trees from private property?
It is the responsibility of private property owners and residents to remove dead or dying Ash trees located on
their property. Once infested with EAB, an Ash tree may die quickly. If you think a tree on your property is
infested with EAB, contact an ISA certified arborist for advice. Safety is the most important issue when
determining when to remove a tree.
Do I need a permit to remove dead or dying ash trees on my property?
Once you have decided to remove your EAB infested ash tree, check to confirm if its removal falls under the Private Tree Protection By-
If you have 3 or more dead, dying or hazardous trees over 15 cm (6 in) in diameter you will need to comply with
the Private Tree Protection By-law. Residents must apply and be approved through the permit process. The City will
waive permit fees if it is determined that the trees are dead or dying.
If you have questions about your privately owned trees and the Private Tree Protection By-law, call 3-1
-1 (905-615-4311 if outside City limit). The Forestry section recommends you contact an ISA certified
arborist to remove the tree.