Emerald Ash Borer Signs in Peoria IL | Save Your Ash Tree

What Is the Emerald Ash Borer?

The emerald ash borer (EAB for short) is a small, metallic-green beetle about half an inch long. The adults don’t do much damage — they nibble on ash leaves for a few weeks in summer. The real destruction comes from their larvae.

After mating, females lay eggs in the bark crevices of ash trees. When the eggs hatch, the larvae bore straight into the tree and tunnel through the tissue just under the bark, carving S-shaped galleries as they feed. Those tunnels cut off the tree’s ability to move water and nutrients between its roots and leaves.

Imagine pinching a garden hose shut — that’s essentially what the larvae do to the tree’s circulation. Do it in enough places, and the tree starves.

EAB was first found in Michigan in 2002 and reached Illinois a few years later, killing hundreds of millions of ash trees since. In the Peoria area, green ash was a favorite street tree for decades — planted along streets, in Bradley Park and Tower Park, and across neighborhoods from the West Bluff to Dunlap. A huge share of our local canopy is at risk.

Why Peoria Ash Trees Are Especially Vulnerable

EAB spreads fastest where ash grows close together, and street plantings along War Memorial Drive, Knoxville Avenue, and Sheridan Road created perfect corridors for it. Add the June 2024 derecho, winter ice storms, and our heavy clay soils, and you’ve got trees with weakened defenses. A healthy ash can sometimes fight off a light infestation — a stressed one usually can’t.

The 5 Signs of Emerald Ash Borer

Walk out to your ash tree and look for these, starting at the top and working down. Early detection is everything with EAB.

1. Canopy Dieback (Thinning at the Top)

The first sign most people notice is a thin-looking top — upper branches leaf out late, produce smaller leaves, or stay bare while lower branches look okay. The larvae’s tunnels disrupt water flow at the extremities first. On its own, dieback just means stress (drought and root damage cause it too), but combined with the signs below, it points strongly to EAB.

2. D-Shaped Exit Holes

This is the smoking gun. When adults emerge in early summer, they chew out leaving holes shaped like a capital D — flat on one side, rounded on the other, only about 1/8 inch across.

Check the trunk and larger branches closely, especially the sunny south and west sides. No other common pest makes that exact mark.

3. Bark Splits and Vertical Cracks

As larvae tunnel beneath the surface, the bark above their galleries dries, splits, and peels away in vertical strips — sometimes revealing the S-shaped tunnels underneath. Last spring a homeowner off Knoxville Avenue called about “rough bark” on their ash; whole sheets were loose, with galleries carved into the wood like winding roads. That tree was too far gone to save.

4. Epicormic Sprouts (Suckers on the Trunk)

Under attack, an ash panics and sends up clusters of leafy shoots straight from the trunk and larger limbs — epicormic sprouts, or suckers. It’s desperately trying to photosynthesize with whatever living tissue remains. Heavy sprouting on the lower trunk, paired with a thinning upper canopy, is a classic EAB symptom.

5. Woodpecker Damage (“Blonding”)

Woodpeckers love EAB larvae. They flake off outer bark to reach them, leaving pale, blond-looking patches — arborists call this “blonding.” A little woodpecker activity is normal, but large light-colored patches up and down the trunk mean they’re likely feasting on borer larvae.

How to Confirm an Infestation

If you’ve spotted one or more of the signs above, here’s how to be sure before you spend money on treatment or removal.

**Check the calendar

Adults fly in June and July, so fresh D-shaped holes in early summer are strong confirmation. Canopy dieback shows most clearly in late spring when the tree should be fully leafed out.

Peel a small bark patch

Lift a palm-sized piece of loose bark on a suspect area — S-shaped tunnels packed with sawdust-like frass confirm larval activity. Don’t strip large sections; you’ll only stress the tree more.

Get a professional assessment

An experienced arborist can read the symptom combination, estimate the infestation’s progress, and tell you straight whether treatment is worth it. We’ve talked plenty of Peoria homeowners out of treating trees past saving — and saved plenty that still had a fighting chance.

Treatment vs. Removal: What Are Your Options?

This is the question every ash owner eventually faces. Here’s the honest breakdown.

Trunk injection.** Is the go-to for valuable ash trees caught early. A certified applicator injects insecticide (usually emamectin benzoate) into the trunk, and the tree’s circulation carries it up to kill feeding larvae. Treatments last about two years and must be repeated for the life of the tree. They work best when the canopy is still more than half healthy — past roughly 50% dieback, treatment usually can’t turn things around.

Soil drenches are cheaper but less reliable, can affect nearby plants and pollinators, and aren’t practical for large trees.

Removal is right when the tree is mostly dead or poses a safety risk. Dead ash becomes brittle fast (arborists call them “widowmakers”), and limbs can drop without warning. If yours stands near a sidewalk, driveway, or your house, don’t let it stand dead.

If your ash is a good candidate for protection, professional emerald ash borer treatment in Peoria, IL starts with an honest evaluation of the canopy and trunk. We’ll tell you whether treatment makes sense or whether your money is better spent on safe removal and a replacement tree.

What About the Wood?

Illinois has had EAB quarantines restricting movement of ash wood and firewood. If your ash gets removed, don’t haul the logs out of the area without checking current rules — ask your tree service before the wood leaves your property.

What EAB Means for Peoria Neighborhoods

Drive through the West Bluff, North Valley, or East Bluff and you’ll see gaps where ash trees stood — streets once lined with green ash now have stumps, young replacements, or empty parkways. The loss goes beyond looks: mature ashes shaded homes, absorbed stormwater in flood-prone riverfront areas, and cleaned air along I-74 and US-150. A sapling takes decades to replace those benefits.

If your neighborhood still has healthy ash, act now — preventive treatment on a healthy tree beats rescue treatment on a declining one every time. And when replanting, diversify with oaks, maples, hackberries, or disease-resistant elms instead of betting on one species again.

Preventing EAB Damage: What Actually Works

Let’s be blunt: no home remedy stops emerald ash borer — not trunk paint, traps, or leaf sprays. Here’s what the research actually supports:

• Professional trunk injections — the only reliably effective treatment, applied by a licensed applicator
• Systemic insecticides applied at the right time — spring applications timed before adult flight
• Keeping the tree vigorous — proper watering during droughts and mulch (not volcano mulch) around the base help the tree tolerate light pressure
• Diversity in replanting — never replace a dead ash with another ash

The Morton Arboretum’s plant clinic has the best EAB identification photos we’ve seen for homeowners, and University of Illinois Extension publishes Illinois-specific EAB updates worth bookmarking if you own ash trees.

One more thing: be wary of anyone who knocks on your door offering to “treat” your ash with a spray bottle or a bag of granules. Real EAB treatment requires specialized equipment and a pesticide applicator’s license. A legitimate arborist in Peoria, IL will explain the product, the timing, and the 2-year retreatment cycle before quoting you a price.

Related Articles

• 20 Years After Emerald Ash Borer: The Surprising Science of Ash Recovery
• Tree Disease Treatment in Peoria, IL: Can a Sick Tree Be Saved?
• Early Signs Your Tree Is Dying or Diseased

Frequently Asked Questions

How fast does emerald ash borer kill a tree?

Usually 2 to 4 years. The first year or two often show no visible symptoms — by the time you see canopy dieback, the beetles have been at work a while. That’s why proactive inspection beats waiting for obvious damage.

Can a tree recover from emerald ash borer on its own?

No. EAB doesn’t leave on its own, and ash trees don’t develop resistance — without treatment, an infested ash will die. Treatment can protect a healthy tree indefinitely, but it must be repeated every couple of years.

Is it too late to treat my ash tree?

If more than half the canopy is healthy and the trunk is mostly intact, treatment is usually worth trying. If the tree has lost most of its crown or shows extensive bark splitting, removal is typically the safer recommendation.

How much does EAB treatment cost in Peoria?

Most companies charge roughly $8–$15 per inch of trunk diameter, so a 20-inch ash runs $160–$300 per treatment, repeated every two years. Against $800–$2,500+ for removal plus a replacement tree, treatment often wins for a healthy, well-placed tree.

Should I cut down my healthy ash tree before EAB gets it?

We don’t recommend it. A healthy ash can be protected with treatment for less than removal costs, and you keep the shade and property value. Remove only if it’s declining or treatment doesn’t fit your budget.

What should I plant instead of ash?

Diversify: swamp white oak, hackberry, Kentucky coffeetree, disease-resistant elm cultivars, and sugar maple all do well here. Match the species to your site — river-bottom wet spots want different trees than dry bluff clay.

Peoria Tree Removal Co. — 114 W Forrest Hill Ave, Peoria, IL 61604 — (309) 250-8333 — treeremovalpeoriail.com — info@treeremovalpeoriail.com