How is the insecticide treatment applied?
Although three insecticides are currently registered in Canada for use for emerald ash borer (EAB), this page focusses on the most commonly used one - TreeAzin™.
TreeAzin™ insecticide is introduced into the tree's conductive tissue. To do this, a series of small holes (4-5 mm) are drilled into the base of the tree, about 15-30 cm above the ground, and small pressurized canisters containing the insecticide are inserted into the holes. The canisters are left in place until the tree takes up the insecticide, and removed when empty. The duration of this treatment depends on a number of factors including the tree's health and size, time of day, time of year and the weather conditions, all of which affect the tree's ability to take up the insecticide. Treatment could take as little as 15-30 minutes, or may take several hours.
TreeAzin™ is a low-risk pesticide with minimal risk to people, pets, other animals, birds or bees. It is classified as a Class 4 pesticide by the Ontario Ministry of the Environment and so is exempt from Ontario's Cosmetic Pesticide Ban. Drilling into the tree does create a wound, but in a healthy tree these wounds recover.