Understanding the Timeline of Emerald Ash Borer Infestation

The Emerald Ash Borer (EAB), a highly invasive species, has been a significant threat to ash trees across the United States, particularly in Minnesota. First discovered in North America in Michigan in 2002, EAB has since spread to most of the eastern U.S. and eastern Canada, including Minnesota. This pest attacks all North American varieties of ash trees, posing a severe risk to the state’s nearly one billion ash trees.

Let’s learn more about how an EAB infestation affects your trees season by season, and what treatment with Valley Green Companies looks like.

Identifying the Enemy: The Emerald Ash Borer

EAB larvae, hatching from eggs laid under the bark, chew through the bark and create “S”-shaped tunnels, disrupting the tree’s nutrient pipelines. As the bark falls off, these tunnels become visible. Adult Emerald Ash Borers leave small “D”-shaped exit holes in the bark. The spread of EAB is primarily through the transportation of infected wood and their ability to fly a few miles each year.

The Micro-Infusion Solution by Valley Green Companies

At Valley Green Companies, we specialize in the micro-infusion method for EAB management, considering it the most effective option for our clients in Central Minnesota. This method involves lightly drilling a tee needle about one inch into the tree and infusing the chemical directly under the bark, allowing for rapid distribution throughout the tree. This treatment, applied every other year, has shown to be highly effective in preventing EAB damage.

The Timeline of EAB Infestation

Understanding the progression of EAB infestation is crucial for effective management. Here’s a general timeline:

Year 0, Summer: EAB adults lay eggs under the bark. The tree appears normal.
Year 0, Fall to Winter: Eggs hatch and larvae begin feeding on the tree’s vascular tissue. The tree still looks normal as it enters dormancy.
Year 0, Spring: Larvae pupate, and some branches may not sprout new leaves. Increased woodpecker activity might be noticeable.
Year 1, Summer: More EAB adults infest the tree, laying numerous eggs.
Year 1, Fall to Winter: A significant increase in larvae feeding occurs.
Year 1, Spring: Up to 30% of the canopy may fail to produce leaves, indicating severe infestation.
Year 2 and Beyond: Without treatment, most ash trees die between 3 to 5 years after infestation.

Seek Treatment

It’s crucial to start treatment as a preventative measure and continue every two years. If an ash tree has lost more than 30% of its canopy, it may be too late for treatment. Early signs like heavy woodpecker activity, bark shedding, and “D”-shaped holes should prompt immediate action.

The Cost-Effectiveness of Micro-Infusion

The cost of treating a 14-inch diameter ash tree every other year is approximately $220, significantly less than the cost of removing and replacing an infected tree.

Valley Green’s micro-infusion method is not only effective but also a financially prudent choice for ash tree preservation.

Let the Professionals Protect Your Canopy

The Emerald Ash Borer poses a silent but deadly threat to ash trees. Early detection and prompt treatment using the micro-infusion method offered by Valley Green Companies are key to protecting these valuable natural assets in Central Minnesota. As the timeline of infestation shows, the window for effective intervention is limited, making awareness and timely action essential.

Worried about an ash tree or group of trees on your property? Give Valley Green Companies a shout. Fill out the contact form or call at (320) 259-5959.