The Emerald Ash Borer: A Nasty Little Bug

A Growing Scourge

In Michigan, we have been dealing with Emerald Ash Borer longer than any other state. Unfortunately, it was brought into our state on pallets from a large boat and it quickly spread to the nearby Ash trees in neighboring communities and subsequently wreaked havoc across the state.

This nasty little bug is native to northeastern Asia where it doesn't cause major damage to trees native to its habitat. Once it made the voyage across the ocean and into our Ash trees, there was very little known about the bug, let alone how to stop it from damaging vegetation. The first sign of the Emerald Ash Borer in the US was in the 1990's. It has quickly spread from the original source in Michigan, east to New Hampshire. and all the way west to satellite areas of Colorado. The wide spread damage caused by the Emerald Ash Borer has resulted in billions of dollars in damages to communities, homes, and cities in these regions.

The More You Know'

The Emerald Ash Borer (EAB) loves to infest Green and Black Ash. Typically, only after those two trees are decimated in a region will they move onto other species, such as White and Blue Ash. EAB lay their eggs in the cracks and crevices of the tree's bark. After hatching, the larvae chew through the bark and into the phloem, the cambium layer, and the outer xylem of the tree.

For those who may be wondering, phloem transports nutrients created through photosynthesis to other parts of the tree where they are needed; xylem transports water and some nutrients from the roots to the upper parts of the tree; and the cambium layer creates both phloem and xylem cells. Now when you think about EAB boring through and munching away at these different parts of the inner bark and wood, you can begin to understand what type of damage they are doing to the infested trees.

EAB larvae tunnel around the trunks of the trees, creating galleries. The galleries look like a zig zagging path back and forth underneath the bark. The tunnels are usually packed with frass (larvae poop) that is white to brown color. The biggest tell-tale sign of an infestation are the D shaped holes in the bark. These holes can be located throughout the tree. Another symptom is an over abundance of sprouts on the trunk of the tree, as well as canopy die back. Lastly, Woodpecker damage is a typical sign that can be seen from far away. Woodpeckers love to feed on EAB larvae.

Addressing the Issue

Once a tree is infested, the home owner is left with three options: let the tree fend for itself; remove the tree; or begin some form of insecticide treatment to counter the pest. From our experience in Michigan, leaving trees to fend for themselves hasn't turned out well for the trees or the home owners. 10's of millions of Ash trees have been devastated by this nasty little bug.

Infested trees tend to have decay below the roots once dead that poses a huge threat to people, houses, and power lines, as well as climbers or workers tasked with removing the trees. As it usually goes, the easiest trees are removed first leaving the large trees in hard to reach places surrounded by power lines and landscaping left for the true professionals or the cowboys. Many companies in Michigan have had to implement a strict no climb policy for Ash trees because of the risks involved with the dead trees.

The other option that is available is injection of a systemic insecticide. A systemic insecticide in injected into the phloem, cambium, and xylem of the tree and then incorporated into the network of the tree. This helps minimize chemical content within the tree. Arborjet has developed TREE-age G4 as a general use insecticide with great results of controlling EAB in Ash trees. The main ingredient in TREE-age G4 is Emamectin Benzoate. TREE-age is known for its 2-year control of EAB, as well as its excellent control as well.

A simple to use and low cost injection system is the Quik-Jet Air from Arborjet. The Quik-Jet Air is a hand controlled injection system that is great for smaller trees with fewer injection sites. The precise measurement system can be set so the proper dose is delivered every time. On projects with many trees or large diameter trees with many injection sites, something like the Quik-jet Air, which uses compressed air to push the chemical into the trees, helps reduce hand fatigue while still injecting the perfect dosage of chemical.

If you have Emerald Ash Borer infestation moving towards you or if it has already been detected in your area, hopefully you can get some insight from what we have witnessed in our own state. If you have clients with large specimen trees in their yards or on their property, you can offer them a little bit of hope with what we have available nowadays through Arborjet. Good luck and stay safe if you have to work around any infested Ash trees!