Emerald Ash Borer | Good News Tree Service, Inc.

There’s a new tree pest in town called the emerald ash borer (or EAB) and it wants to kill all the ash trees in this area.

The Emerald Ash Border (or EAB) was discovered in the summer of 2022 in hundreds of trees in the Portland Metra area and is spreading rapidly throughout the region.

According to the Oregon Department of Agriculture, the EAB “is a highly destructive invasive forest pest” that has killed over 100 million ash trees so far in the US. It moves quickly, and can cause nearly complete mortality of ash trees within about several years after detection. There are no effective means of eradicating the EAB once the insect is established in an area. Once a tree canopy has been thinned or been reduced by 20 to 30 percent or more by EAB feeding activity, it is too late to save the tree. It will die.

Good News Tree Service, Inc. can save your ash tree from the EAB beetle before it’s too late. CALL US TODAY FOR MORE INFO!

Frequently Asked Questions About the EAB

What trees species does the Emerald Ash Borer attack?

The EAB attacks all varieties of ash or Fraxinus trees regardless of variety, size, age or the health status of the tree. It also attacks the white fringetree (Chionanthus virginicus) and cultivated olive trees (Olea europaea).

How quickly does EAB spread?

The beetle can fly several miles (sometimes up to 15 miles) from one infested tree to one that is not. However, the most likely means by which the EAB spreads is thought to be by hitchhiking on vehicles and by translocated firewood. That’s why the EAB is more likely to spread to trees in areas along major freeways and highways, which opens up the entire Willamette Valley to the EAB.

How quickly will the EAB kill my tree?

An ash tree usually dies within four to six years after initial infestation. For the first couple of years of EAB infestation, it may be impossible to detect EAB activity in a tree, which is why trees worth saving need to be treated earlier rather than later.

What are the signs that my tree has EAB?There are several including:

Thinning of a tree’s crown.
Branch dieback.
Woodpecker activity.
One-eighth inch sized capital “D” shaped holes in the bark of the tree.
Splitting bark.

Progression of EAB symptoms in a tree, which may occur a couple of years after the tree has already been infested include:

Year one: no crown thinning.
Year two: moderate crown thinning.
Year three to four: heavy crown thinning and death.

What are my options when it comes to EAB?

Do nothing. Then wait for your tree to die as you unwittingly facilitate the spread of the EAB to your neighbors’ ash trees.
Remove the tree. If your ash tree is small (smaller than six inches in diameter), we recommend removing it and replacing with another species of tree. The cost to remove an ash tree and its stump can be $1,500 or more. This does not factor in the diminished value to your property that the removal of a mature tree will cause. In Portland, for example, the assessed value of mature ash tree is $3,1201³. Plus, this not cover the cost to replace the tree, which is often a requirement in many municipalities.
Treatment. Considering treating high-value ash trees with an insecticide, which is a proven way of protecting your tree. Keep in mind that this will cost hundreds of dollars and must be repeated every few years, thus requiring a long-term commitment.

Is there anything I can do to protect my ash tree?

Other than treating your tree with a systemic insecticide, the answer is no.

How effective are treatments?

If an ash tree is treated in time, usually before 20 to 30 percent defoliation occurs, the survival rate is about 99 percent. After that level of defoliation occurs, will die the tree thus becomes a standing hazard requiring removal.

What is the cost to treat my ash tree for EAB?

The cost to treat an average sized ash tree (20 inch diameter at breast height) is around $300 to $400 (or less for quantity discounts). Generally one can treat an ash tree for 20 to 30 years for the same cost as removing it and replacing it with another tree. Often local municipalities require that you replace your tree especially if it is a street tree, which adds to the overall cost of removing a tree.

How often do I need to treat my tree?

An ash tree will need to be treated only once very two to three years, and will need to be treated for the life of the tree.

How are the treatments applied and are they environmentally safe?

Yes! Absolutely. The systemic insecticide we use is injected directly into the tree’s vascular system (like and IV), so it all goes into the tree, thus there is no residue present to harm pets or people. The product we use also doesn’t harm bees or other pollinators.

More Info About EAB

Oregon State University Extension Service— general info: https://extension.oregonstate.edu/forests/cutting-selling/what-do-about-emerald-ash-borer-recommendations-tree-protection-eab

Oregon State University—EAB identification guide: https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9160.pdf

OSU Extention Service–general info and more links: https://extension.oregonstate.edu/announcements/emerald-ash-borer-quarantine-adopted-washington-county-effective-dec-20-2022-may-16

OSU Extention Service:
https://extension.oregonstate.edu/forests/cutting-selling/what-do-about-emerald-ash-borer-recommendations-tree-protection-eab