Our Guide to Emerald Ash Borers

Of all the tree-destroying insects in North America, there is one that is familiar to nearly all gardeners and homeowners—the Emerald Ash Borer. Read our guide to help you figure out if this pest has infested your yard.
What is an Emerald Ash Borer (EAB)?
The emerald ash borer beetle is an invasive pest that was first detected in the United States in 2002 and has since then spread across thirty-five states and killed more than fifty million trees, decimating the US’ ash population. The infestations are continuing to spread throughout the country—and once a forest has become infested, it is expected to lose all of its trees within 10 years.
How to Identify an Emerald Ash Borer
Emerald ash borer adults are tiny, metallic green beetles, about the size of a grain of rice. But it is the larvae, which are cream-colored worms with bell-shaped segmented bodies, that cause damage to trees. As soon as they emerge from their eggs, they begin to tunnel into the cambial layer of the tree. They wind back and forth carving S-shaped galleries in the wood.
Learn how to identify EAB damage and what treatment options to consider.
Where Are Emerald Ash Borers Active?
Since its discovery, the EAB has spread across 35+ states in the US and counting. Many states and counties have put restrictions on the transportation of firewood in order to mitigate the spread of these deadly insects.
When Are Emerald Ash Borers Active?
EAB emerges from under the bark of ash trees beginning in late May or early June and are most active between mid-June and early July. They are visible during sunny, warm days and shelter under bark or foliage when it is rainy or cold.
Other Types of Ash Borers
Aside from the emerald ash borer, which is the most widespread and dangerous of the ash borer family, other common ash borer species include:
- Lilac Ash Borer
- Clearwing Moth
- Ash Bark Beetle
- Ambrosia Beetle
Why Are Emerald Ash Borers Dangerous?
After they hatch, the larvae of the EAB bore into the ash tree and feed under the bark, carving large galleries in the tissues of the tree. This disrupts the tree’s ability to transport water and other nutrients.
Are Emerald Ash Borers Dangerous to Humans?
Emerald Ash Borer beetles are not dangerous to humans, as they do not bite or sting. But a 2014 study did find a correlation between the trees being infected and killed by EAB and an increase in deaths caused by cardiovascular and lower respiratory diseases.
How Do Emerald Ash Borers Spread?
EAB spreads mostly through infested firewood transported by humans. To prevent the spread, do not transport infected firewood across state or county lines.
Call The Tree Care Experts At American Turf and Tree Care
Your trees and ornamentals are an important investment in your property. That’s why we have been providing proven emerald ash borer treatments that focus on EAB prevention and removal. Our tree care professionals know how valuable your trees are to your property and we will take the best care of them.
FAQ About Emerald Ash Borers
Here are some common questions are team gets asked when it comes to identifying an EAB infestation
Originally from Asia, the emerald ash borer's native range includes:
- Russia
- Mongolia
- Japan
- China
- Taiwan
It is unknown how long the pest has been in the country, but the first detention was in southeastern Michigan in 2002.
After hatching in 7-10 days, the larvae feed under the bark and go through five instars before they reach adulthood. An adult EAB can live for up to 3 weeks.
How long a tree can survive an EAB infestation depends on the size of the tree in relation to the severity of the infestation level. With high EAB populations, small trees may die within 1-2 years while larger trees can be killed in 3-4 years.
All types of ash trees are susceptible to Emerald Ash Borers, including:
- Black Ash
- Blue Ash
- California Ash
- Carolina Ash
- Green Ash
- Gregg’s Ash
- European Ash
- Manchurian Ash
- Manna Ashe
- Narrow-Leaved Ash
- Pumpkin Ash
- Velvet Ash
- White Ash