The ash tree is a beautiful shade tree that provides a stunning canopy that blocks sunlight to many yards. The ash tree has replaced elm trees in many communities where Dutch elm disease wiped out entire tree populations. Ash trees grow very quickly, up to 24 inches each year, and grow well in many types of soil conditions. They are hardy and able to grow in many different climates.
Their one big enemy, the emerald ash borer beetle, is attacking the trees. Learn more about the emerald ash borer in Ontario to understand why you should act quickly if you discover one of these insects on your trees.
The Life Cycle of the Emerald Ash Borer
The emerald ash borer is a small beetle. Its scientific name is Agrilus Planipennis. You can recognize an adult insect by its green metallic color. These beetles are most active in late spring and early summer when they are mating. The adults feed on ash leaves. Females leave their eggs under bark scales or in crevices in the bark. The larvae of the beetle go through multiple stages. Larvae feed off the nutrients in the tree, which is what kills the tree.
How To Spot the Emerald Ash Borer in Your Ash Trees
By the time homeowners see symptoms of emerald ash borers in trees, it’s likely that the tree is heavily infested. New infestations of the emerald ash borer are harder to detect. However, once a tree has been identified as infested you can often save the tree and prevent other trees from further spread. Here are signs to watch for:
- S-shaped or zig-zag galleries under the bark of the tree: young larvae move through the tree bark and sapwood in a zig-zag fashion. When the bark is pulled away, you can see this pattern.
- Exit holes: when the larvae become adults, they chew holes in the bark to exit. Keep in mind that many different types of beetles can make these types of holes. An arborist can help determine which type of insect is living in the tree.
- Leaf notches: adult beetles feed on the leaves, causing ragged patterns along the edge of the leaf.
- Epicormic shoots: trees stressed by an EAB infestation may develop sprouts on trunks.
- Thinning crown: branches die, causing the leaves at the top of the tree to fall off.
- Bark deformities: infested trees may develop splits or vertical cracks within the bark.
- Damage from birds or other animals: woodpeckers and other birds feed off the larvae and can damage the trees.
Emerald ash borers are a serious problem in northeast North America. The beetle has already killed millions of trees across Canada and the United States. Although emerald ash borer damage can take a few years to completely kill the tree, without treatment the tree is sure to be lost. In addition, all the ash trees in the community could become infested. The emerald ash borer is not native to Canada, and there are no natural predators that kill the parasite, giving this small insect an outsized hold over the ecosystem.
What You Can Do if Your Trees Have Emerald Ash Borers
Emerald ash borers are treated with systemic insecticides that are directly injected into the diseased trees. This treatment can only be done by trained professionals. Typically, the tree will need to be retreated every one to two years to protect the tree. Infested trees can be successfully treated, which saves your landscape. If you find an emerald ash borer on the tree, collect an adult insect and place it in a container in your freezer to kill it. Record the location of the tree or mark it so you can find it later. Contact Martin’s Tree Service for treatment to save your trees from continued damage.