Emerald Ash Borer Emergence Prep

Each year, emerald ash borer (EAB) poses a threat to ash trees across large swathes of the US. It is the most destructive invasive pest in the country right now, responsible for the death or removal of over 10 million ash trees.

Emerald ash borer adults typically emerge in May. Now is the right time of year to begin preparing for Emerald Ash Borer. This is your window of time to prevent this from becoming an issue during the growing season.

What is Emerald Ash Borer?

Emerald ash borer (Agrilus planipennis) is an invasive woodboring beetle native to parts of Asia. It was first discovered in the US in Michigan in 2002. This insect targets ash trees almost exclusively. Larvae burrow into the tree bark and feed on the cambium layer, the part of the tree that moves nutrients between the roots and the upper branches.

This girdles the tree and can lead to death of even mature ash trees in just a few short years. Adult beetles can fly about a quarter mile to reach new ash trees, but their spread can also be facilitated by human movement of wood infested with larvae.

What’s At Risk?

Ash trees can make up a large part of urban forests, including as shade trees along streets and sidewalks. Communities impacted by EAB can lose large expanses of shade trees in a short period of time, which rapidly changes the neighborhood’s character and feel. Streets and neighborhoods without trees become exposed to sun, wind, and noise, and property values decline without old shade trees. Dead and dying ash trees are also expensive and unsafe to remove. It is far more cost-effective and beneficial to the city populace to act proactively to protect vulnerable ash trees than to cut down and replace them.


How Do You Know If You’re Infected?

Check for general signs of ash tree decline, such as branch dieback, woodpecker damage, and epicormic sprouting. Direct damage left by EAB is hard to detect; it will either be very small D-shaped exit holes left by emerging adults (about an 1/8 of an inch), or S-shaped larval galleries just under the surface of the bark. Checking for signs of leaf damage (which the adults will feed on) is not typically a successful method.

EAB can kill ash trees in just a few years, so pay close attention to ash trees that seem to be suffering from a very sudden decline in health.

Serpentine mines, the result of larval mining
Serpentine mines, the result of larval mining

What Products Can I Use?

Here’s a look at the products that professionals can use to help against Emerald Ash Borer:

  • TREE-äge R10: an injectable and systemic emamectin benzoate that provides up to two years of control. Our most reliable product with repeated successful results in protecting ash trees, the TREE-äge brand has been used by municipalities on public trees for over a generation. The tree injection methodology with the use of plugs keeps the product sealed inside the tree, reducing expose to off-target pests, people, and waterways.
  • TREE-äge G4: Another emamectin benzoate solution to control insect pests for up to two years. This is a General Use Product with a 4% concentration.
Systemic tree injection using the QUIK-jet Air
Systemic tree injection using the QUIK-jet Air

Though it has been a large problem for a while in the US, emerald ash borer can be a manageable problem. With the right treatments applied at the right time, and by keeping track of the most at-risk areas of the country, you can ensure your ash trees stay protected and safe.


©2024 Arborjet, Inc. Important: Always read and follow label instructions. Some crop protection products may not be registered for sale or use in all states or counties. Please check with your state or local extension service to ensure registration status. TREE-äge® Insecticide is a Restricted Use Pesticide and must only be sold to and used by a state certified applicator or by persons under their direct supervision. TREE-äge® is a registered trademark of Arborjet, Inc.