Emerald Ash Borer



The Emerald Ash Borer is a bright metallic green wood boring beetle, it has a coppery-reddish or purple color to the abdomen. They usually measure anywhere from 8-14mm long. They have a flattened head, with large black eyes on the sides of their head and they have a short antenna. 

Here's a quick history...


The Emerald Ash Borer is an invasive insect that originally came from Asia. In 2002, it was first found in North America, but it is suspected it has been around since the early 1990s. The Emerald Ash Borer attacks & kills true ash or Fraxinus species, but it does not affect the Mountain Ash or sorbus species! Since the Emerald Ash Borer has been introduced – it has spread substantially throughout southern & central Ontario, unfortunately killing millions of trees.   The Emerald Ash Borer was discovered in southern Simcoe County in 2013. By 2016 it had been found in over half of our local municipalities within our County. 

How is it killing our trees?

 Adult beetles appear from under the bark of our Ash Trees in May to August. After they rise, they feed for about a week and then they start mating. The female insects then lay 40-70 very small eggs in a crevice or fold in the bark of the Ash Tree. Within 2 weeks, the eggs hatch. The new larvae bore into the tree where they feed on the living tissue underneath the bark, producing serpentine or S-shaped feeding galleries until fall. The larvae then dig a chamber in the bark where they stay for the winter. The next spring, the larvae pupate and come out as adults by burrowing out of the tree and through the bark. They leave a D-shaped exit hole. The feeding galleries that the beetle create, hurt the flow of nutrients and water in the Ash Tree and cause the tree to die from the top down, epicormic shoots, and peeling bark. Death in affected trees can happen in as little as 1-2 years. The Emerald Ash Borer attacks and kills Ash Trees of all shapes and sizes, or any age. It kills more than 99% of trees it infects. 

What to do if you suspect your tree is infected...


It is the landowner’s responsibility to take care or remove trees on their own property. If you have an Ash Tree on your property that doesn’t seem infected or is in the early stages of infection, it is highly recommended that you start treating your tree as soon as possible with a register insecticide to increase survival. 

If your tree seems infected, you should call an arborist/forestry professional and get an expert opinion. Most trees that haven’t been treated as directed – will eventually die and should be removed.  We always recommend removing your infected trees before it becomes dangerous, weak or rotten – this is for safety reasons and to help you save some money! The more dangerous the job, the higher the cost. 

More information...

Here are a few links that we believe to be beneficial if you would like to learn more!


The County of Simcoe