Emerald Ash Borer in Texas: What Austin Homeowners Need to Know

Emerald Ash Borer in Texas: What Austin Homeowners Need to Know

‍

The emerald ash borer (EAB) has devastated ash tree populations across North America, killing hundreds of millions of trees since its arrival in the United States. It’s now confirmed in Texas, and Austin homeowners with ash trees need to understand what they’re dealing with. This pest does not resolve on its own — untreated ash trees will die, typically within two to five years of infestation. Here’s what you need to know right now.

‍

What Is the Emerald Ash Borer?

‍

The Biology

‍

The emerald ash borer is a metallic green beetle native to Asia that exclusively targets ash trees. The adult beetle causes minimal damage — it’s the larvae that kill trees. After adults lay eggs in bark crevices, the larvae bore into the inner bark and cambium, creating S-shaped feeding galleries that disrupt the tree’s ability to transport water and nutrients. A heavily infested tree essentially starves to death from the inside out.

‍

Which Austin Trees Are at Risk

‍

All native North American ash species are susceptible to EAB. The most common in Austin yards and streetscapes include Texas ash (Fraxinus texensis), Arizona ash (Fraxinus velutina), and green ash (Fraxinus pennsylvanica). If you have any ash tree on your property, it should be evaluated now — not after symptoms appear, when treatment options are significantly more limited.

‍

How to Identify an Infestation

‍

Early Signs

‍

EAB is notoriously difficult to detect in its early stages because larvae work beneath the bark invisibly. Early warning signs include thinning canopy from the top down, increased woodpecker activity (woodpeckers feed on larvae), and small D-shaped exit holes in the bark roughly the size of a pencil tip. Epicormic sprouting — small shoots emerging from the trunk and major limbs — is a common stress response in infested trees.

‍

Advanced Infestation

‍

By the time you can see obvious canopy dieback, bark splitting, and widespread D-shaped exit holes, the infestation is advanced and treatment efficacy is significantly reduced. Trees that have lost more than 50% of their canopy are generally beyond treatment and need to be removed before they become hazards.

‍

Treatment Options

‍

Systemic Insecticide Treatment

‍

For trees with less than 50% canopy loss, systemic insecticide treatments — applied as soil injections, trunk injections, or bark sprays — can be highly effective at stopping EAB and allowing trees to recover. Emamectin benzoate (trunk injection) and imidacloprid (soil injection) are the most commonly used and research-supported treatments. Treatment must be repeated every one to three years depending on the product used, and should be started before infestation becomes severe.

‍

Is Your Tree Worth Treating?

‍

Treatment makes financial sense for large, healthy, structurally sound ash trees in prominent locations. The cost of ongoing treatment should be weighed against the cost of removal and replacement. At Agave Tree Services, we help Austin homeowners make these decisions based on tree health data — not sales incentives. If you have ash trees on your property, reach out for an evaluation before EAB does the deciding for you.

‍