Emerald Ash Borer - Town of Ajax

Emerald Ash Borer FAQs

What is the Emerald Ash Borer (EAB)?
The EAB beetle is a non-native invasive insect, it attacks and kills most varieties of ash trees (white and green ash). EAB is confirmed in the Town of Ajax. Adult EAB beetles lay their eggs on ash trees in the summer. When the eggs hatch into larvae, they tunnel under the tree's bark to feed. The tunnels prevent the flow of water and nutrients, causing the tree to die.

Where did EAB come from?

The EAB beetle originated in Asia, and is believed to have come to North America in the early 1990's, via the transportation of ash wood materials. It was first detected in Canada in 2002 in Windsor, Ontario. It has since killed and infested over 70 million ash trees.

How does EAB spread?
EAB spreads through the transport of infested ash wood materials. To prevent the spread of EAB, don't move firewood, and buy wood locally.

Where has EAB been found in Ajax?
EAB has been confirmed in the northwest quadrant of the Town. However, EAB beetles can fly long distances up to 5 km, and is suspected to be present throughout the town.

What is TreeAzin™?
TreeAzin™ is a systemic insecticide injected into the tree's bark, directly into the conductive tissues, and moves upward with the flow of water and nutrients. It kills EAB larvae feeding on the tree's tissues by regulating growth and disrupting normal molting. It does not pose any health risk to people, pets or wildlife and degrades naturally. To be effective, it is re-injected into the tree every two years.

How will EAB impact the Urban Forest in Ajax?
Ash trees make up approximately 7% of the town's urban forest, on both private and public property. The Urban Forest has an inherent value and provides us with numerous benefits - helping clean the air we breathe, shading us from harmful UV rays, beautifying our town and many others. Untreated ash trees are expected to be impacted or killed by EAB over the next 10 years.

What is the Town of Ajax doing about EAB?
The Town is currently implementing its EAB Management Strategy, which aims to reduce the significant aesthetic, environmental and financial impacts of the EAB. This is being done through a combination of monitoring, treatment, ash tree removal and replacement, and public education. Private property owners are responsible for trees on their property.

Possible Signs of EAB Infestation
There are a number of possible signs that could indicate a potential EAB infestation.

 Emerald Ash Borer - Figure 1 Emerald Ash Borer - Figure 2 Emerald Ash Borer - Figure 3 Emerald Ash Borer - Figure 4
Figure 1Figure 2Figure 3

Figure 4

Dead branches or discolored foliage which can be observed during late summer. Feeding by the larvae kills branches and eventually the trees (approx. 1-4 years). See Figure 1Close examination of the bark may reveal D-shaped holes. When new adults emerge from the tree they create this hole to leave the tree. These holes are approximately 3.4 to 4 mm wide. See Figure 2If the bark is peeled back S-shaped tunnels may be visible. This is from the larva feeding between the bark and sap wood. See Figure 3 and 4 

Other Possible Signs of EAB Infestation:

  • Bark deformities
  • Heavy seed production
  • Chewed leaves

How do EABs impact Ash Trees?
EAB kills ash trees by eating their nutrients. As larvae, they are located between the bark and sap wood and eat the trees nutrients. As adults, EABs eat ash tree leaves. Both of these actions, including the fact that EABs do not have any natural predators lead to infestation and eventual death of the tree (approx. 1 to 4 years).

What should I do if an ash tree on my property is infested?
Property owners who suspect an EAB infestation are encouraged to contact a professional arborist, certified with the International Society of Arboriculture (ISA) or the American Society of Consulting Arborists.


Contact Information
If you have any questions about EAB feel free to contact any of these organizations for more information:

Town of Ajax Operations & Environmental Services

The Canadian Food Inspection Agency

Canadian Forest Service

Durham Region

 *All photos courtesy of the Ministry of Natural Resources