Emerald Ash Borer Fact Sheet
The Emerald Ash Borer (EAB) is native to Asia. It was probably imported into Michigan 10-15 years ago via shipping containers.
The EAB was discovered during June 2002 in south east Michigan. Since then, more than forty million Ash trees have been infested and killed in the United States.
The EAB is predicted to cause an unprecedented $10 – 20 billion in losses in urban forests over the next ten years.
A study by the U. S. Forest Service found there to be more than 3.8 billion White Ash trees in Ohio.
The EAB is now the most invasive insect in North America.
In Ohio, the EAB has been found in 59 of 88 counties (as of May 2012), including Clark, Greene, Miami, Montgomery and Warren counties.
If the EAB is found within 15 miles of your location you need to consider your options, which include:
1) treat ash trees with insecticides.
2) remove ash trees.
3) remove ash trees and replace with another non ash tree.
If a tree has less than 50% canopy decline it is worth trying to save.
Trees infested with EAB do not show symptoms until 1 - 4 years after infestation.
Not all ash trees are worth saving. Make an assessment of your property. Save trees that provide shade for your home, are a focal point in the landscape and provide high value to your property.
The life cycle of the EAB:
The adult emerges from infested trees in late May through early August. As they emerge, they leave a small D shaped exit hole in the trunk. Adults live 3-6 weeks, feeding on Ash leaves (which cause no damage to the tree). The female will lay approximately 50 -100 eggs on the bark surface. When the eggs hatch the larvae will tunnel into the tree, where they feed on the phloem and outer sapwood, disrupting the flow of nutrients and water between the canopy and roots. This is what causes eventual death to the tree. Larvae continue to feed through the summer and into autumn. They over-winter and in the spring pupation occurs. Adults emerge to complete a typical one year life cycle.
Signs and symptoms of EAB presence:
EAB infestations are usually difficult to detect until they become severe because the larvae are under the bark and adults spend most of their time in the upper canopy of the tree. On larger trees, EAB usually colonizes the upper trunk area, making diagnosis difficult from the ground. Small, vertical bark splits can occur when the larvae are present. These splits can be enlarged to reveal larvae and galleries (the
S shaped feeding pattern). Also look for D shaped exit holes in the trunk or large branches. Branch dieback and canopy thinning will start from the top of the tree. Sucker growth (epicormic shoots) from the main trunk is also an indication of EAB presence, as is increased woodpecker activity. Complete tree death occurs within two to four years of initial infestation.
Will the EAB kill other trees?
The EAB infests only ash trees. Those found in Ohio include: Black Ash (Fraxinus nigra), Green Ash (F. pennsylvanica), White Ash (F. americana) and Blue Ash (F. quadrangulata).
The EAB will not infest Korean Mountainash (Sorbus alinifolia) or European Mountainash (S. aucuparia).
Is it less expensive to remove the tree than treat it?
Removal of ash trees may be more expensive than treatments. A large ash tree located near a building may cost as much as $2,000.00 to remove. Keep in mind that if you want a new tree where the ash was removed there is also the expense of a backhoe to dig out the ash stump. The loss of a large tree may significantly reduce property value. Visit www.treebenefits.com, this will help you determine the economic value your ash tree provides to your property.
This fact sheet has been written by Steve Kuflewski, founder and owner of Village Landscaping LLC. Graduate of The Ohio State University, College of Agriculture, Department of Landscape Horticulture, 1977.
This information has been gathered from many sources, including: extension publications from The Ohio State University, Michigan State University, Purdue University, Penn State University, University of Illinois, University of Wisconsin; The American Nurseryman; webinars; seminars; and various web sites.