Bug Identifier

Beetles

Emerald Ash Borer

Agrilus planipennis

048121620
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameAgrilus planipennis
GroupBeetles
Size8–14 mm (up to about 0.55 in)
Colors Green and Metallic
Legs6 legs
WingsYes
Where foundTrees or shrubs
Most activeSummer
BitesNo
StingsNo
Risk levelNuisance

How to identify it

The emerald ash borer is a small member of the beetles group. Hard wing covers that meet in a straight line down the back. Check for these three features:

  1. Bright metallic emerald green body
  2. Coppery-red upper abdomen visible when the wings open
  3. D-shaped exit holes about 1/8 inch wide in ash bark

About this bug

A slim, bullet-shaped, metallic green beetle whose larvae tunnel beneath ash tree bark. It has killed hundreds of millions of ash trees across North America.

You'll usually find emerald ash borers on trees and shrubs. They are most active in summer.

Is it dangerous?

Emerald ash borers are harmless to people but lethal to untreated ash trees.

Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.

When you'll see emerald ash borers

Emerald Ash Borers are most active in summer. Summer heat speeds up development, so populations can grow quickly.

Typical places to check: trees or shrubs.

About beetles

The emerald ash borer is one of the beetles. Beetles go through complete metamorphosis: egg, larva (grub), pupa and adult. The larval stage often does the most feeding and damage, and it can last from a few weeks to several years depending on the species. Adults protect their flight wings under hard wing covers called elytra, which is why most beetles look armored and meet in a neat line down the back.

Look closely at larvae as well as adults. Grubs in soil, fuzzy larvae in closets and small worms in flour are all beetle larvae, and finding them tells you where the problem is centered.

What to do about it

  1. Check ash trees for canopy thinning, bark splits and D-shaped holes
  2. Have a certified arborist evaluate systemic treatment for valuable ash trees
  3. Don't move firewood; buy or gather it where you will burn it

Read the full guide: how to get rid of emerald ash borers.

Bugs that look similar

Japanese BeetlePopillia japonica10–15 mmNuisance

Color: Emerald Ash Borers are green and metallic; Japanese beetles are green, metallic and brown.

Frequently asked questions

What does an emerald ash borer look like?

Bright metallic emerald green body. Adults measure 8–14 mm (up to about 0.55 in).

Does the emerald ash borer bite or sting?

It does not bite. It does not sting. Emerald ash borers are harmless to people but lethal to untreated ash trees.

Where do emerald ash borers live?

Emerald Ash Borers live on trees and shrubs.

When are emerald ash borers most active?

Mostly in summer.