Protect Your Property from Emerald Ash Borers: Tree Removal Options

Ben Stein, the Tree Guy
Aug 9
3 min read

What is the Emerald Ash Borer?

The emerald ash borer (EAB) is an invasive beetle that arrived several years ago in the state and poses a significant threat to ash trees in Hancock county, including all of Mount Desert Island, Ellsworth, and surrounding towns.

Native to Asia, the insect infests and kills ash trees by burrowing under its bark and disrupting the flow of nutrients. In Maine, the EAB has been detected in several areas, particularly in southern and central regions, including parts of Cumberland, York, and Androscoggin counties. It was recently detected and confirmed on Mount Desert Island and has been spreading further each season.

emerald ash borer. agrilus planipennis — The emerald ash borer is a small, narrow, metallic-green beetle about ½ inch long with a bullet-shaped body and coppery-red or purplish highlights.

What are signs that my ash tree is infected with EAB?

Your ash tree may be infected with the emerald ash borer when you notice thinning or dying branches, particularly in the upper canopy, and unusual "D-shaped" exit holes in the bark. You might also notice vertical splits in the bark, and the tree may produce excessive sprouting at the base. If the infestation is severe, the tree may start to show signs of overall decline and eventual death. Early detection is key, so it's important to inspect your trees regularly.

If you think that you see signs of infection, call an ISA certified arborist as soon as possible to confirm it is EAB and ask about interventions.

Here's a quick list of what to look for:

D-shaped exit holes — Tiny (about ⅛ inch across) and flat on one side, where adults emerge from under the bark.
S-shaped larval galleries — Winding tunnels just beneath the bark, packed with fine sawdust, made by feeding larvae.
Canopy dieback — Thinning leaves and dead branches starting in the upper third of the tree and progressing downward.
Epicormic shoots — New shoots or “water sprouts” growing from the trunk or base as the tree tries to survive.
Bark splitting — Vertical cracks exposing the larval tunnels underneath.
Woodpecker activity — Increased woodpecker holes and flaking bark as they hunt for larvae.

What are the hazards of having an ash tree infected with EAB?

Having an ash tree infected with the emerald ash borer near your property can pose a significant risk. In areas like Mount Desert Island, where ash trees are common, these weakened trees are more prone to failing, especially during storms, which can cause damage to property, power lines, or even pose a safety risk to people nearby.

It's important to contact a professional tree service or certified arborist to assess the situation. If the tree is too far gone, timely tree removal may be necessary to prevent further damage or injury. Removing the tree as soon as possible is important, as the longer an infected tree stands, the weaker it becomes.

What are my options? Can my ash tree be saved?

We often get the same question from property owners: “Do I have to cut it down, or can I save it?”

The short answer: Yes, there are treatment options, from professional trunk injections to soil-applied insecticides and bark sprays. Each of these requires regular reapplication for the life of the tree to remain effective. But in most cases, the safest plan, both for your property and your surrounding trees, is removal. Treating an ash for EAB is a commitment for the life of the tree, and even then, there’s still a risk of spreading the pest to other ash nearby.

Ash trees that are infected with EAB should be removed as soon as possible. As the trees condition deteriorates, it becomes more dangerous and difficult to climb, remove, and work with.