Public notice of pesticide use in 2025 for control of Emerald Ash Borer (Agrilus planipennis)

Emerald Ash Borer (EAB) is an invasive beetle, not native to North America, that has been present in the GTA since 2007. EAB is an aggressive, invasive insect that has killed millions of ash trees throughout Ontario. There are currently no native, natural controls to keep EAB populations low enough to avoid tree mortality.

To protect vulnerable ash trees from EAB, the Town has been injecting select, Town-owned ash trees with TreeAzin Systemic Insecticide (Pest Control Products # 30559) since 2011. TreeAzin, derived from Neem tree seeds, contains the active ingredient Azadirachtin, which acts as a growth inhibitor for insects when ingested. TreeAzin is registered by Health Canada’s Pest Management Regulatory Agency (PMRA) under the Pest Control Products Act (Canada) for control of EAB. This pesticide use is in accordance with the public health and safety exception to the cosmetic pesticide ban in subsection 7.1 (2) of the Pesticides Act and is considered a class C pesticide. TreeAzin is listed by the Organic Materials Review Institute (OMRI) for organic use.

Approximately 1,600 Town-owned ash trees are scheduled to be injected from June 20, 2025 to August 31, 2025. TreeAzin is injected into the trunk of the tree using EcoJect injection canisters that are inserted into drilled holes. TreeAzin is pushed into the tree’s vascular tissue and transported throughout the tree underneath the bark. EAB larvae that feed upon tissue that contains TreeAzin will be affected and will not reach maturity.

To find out which ash trees will be injected, visit the Town of Oakville’s interactive Tree Inventory map.

If you have any further questions regarding the EAB injection program, please connect with Service Oakville at 905 845 6601, toll-free at 1-877-625-8455 or service@oakville.ca to get in touch with Town staff who will answer your questions.