Emerald Ash Borer (EAB), members of the genus Fraxinus, is a non-native insect that is currently attacking ash trees throughout the country. First identified in southeastern Michigan in July 2002, emerald ash borer has already killed more than 10 million ash trees in Michigan’s cities and forests. Emerald ash borer is a selective pest; it’s larvae feeds only the cambium between the bark and wood of ash trees. This produces galleries (look like mazes on bark) that eventually girdle and kill branches and entire trees. Infested ash trees have also been found in Maryland and Virginia.
The spread of emerald ash borer is unlikely to be effectively contained. Many communities have discontinued the planting of new ash trees and are now making plans for how to manage future EAB losses. To assist with recovery, Ohio State University Forestry Extension has assembled a publication that identifies tree species that can be used to replace existing ash, when appropriate, or used in future plantings if ash species are not available or are inappropriate for planting.
The Emerald Ash Borer Threat
Adults are slender and 7.5-13.5 mm long. Color varies but adults are usually bronze or golden green overall, with darger, metallic, emerald green wing covers. The top of the abdomen under the wings is metallic purplish red and can be seen when the wings are spread.
Larvae reach a length of 26-32 mm, are white to cream-colored, and dorso-ventrally flattened. The brown head is mostly retracted into the prothorax and only the mouth-parts are visible externally. The 10-segmented abdomen has a pair of brown, pincer-like appendages on the last segment.
To learn more about emerald ash borer (including how to identify the insect and its damage), identify ash trees, or obtain a diagnostic check-list to help determine if your trees and woodland are infested with emerald ash borer, visit the Ohio State University Extension.
Selecting the Tree Species to Plant
In developing this guide for selecting tree species to use to replace ash, it was assumed that, if not for emerald ash borer, one or more of the ash species would be suitable for the planting. Tree species included in this guide, therefore, are generally of the same size as ash and grow well on sites suitable for one or more of the native ash species. You will not, for example, find tree species in this guide that grow to a maximum height of 25 feet and which would be suitable for planting under utility power lines, as ash would not be an appropriate tree for such a planting.
Ohio State University Ash Replacements Guide
Yu, Chengming. 1992. Forest insects of China. 2d ed. Beijing, China: China Forestry Publishing House; 400-401.
Jendek, E. 2002. Agrilus planipennis fact sheet. Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovak Republic.