What is the Emerald Ash Borer?
The Emerald Ash Borer (EAB), Agrilus planipennis, is an exotic insect that was discovered and identified in Southeast Michigan in the summer of 2002. It is a invasive pest that affects ash trees and belongs to a group of insects known as metallic wood-boring beetles.
Where did it come from?
At this point no one knows specifically how it arrived in Michigan. It is not native to the state or anywhere else on the North American continent. The natural range of the Emerald Ash Borer is northern China, eastern Russia, Japan, and Korea .What types of trees does the Emerald Ash Borer affect?
To the best of our knowledge it has only been found on ash trees, hence its name. Trees in wood lots as well as landscaped areas are affected. For the most part, affected trees appear to be at least 2 inches in diameter and larger. NOTE: An ash tree can be identified by its distinctive leaves and bark. Ash trees have several leaves per leaf stem and the leaves are located directly across from each other. Where has it been found?
To date, infested areas have only been found in Livingston, Macomb, Monroe, Oakland, Washtenaw and Wayne Counties. Inspections are continuing in other areas of the state. It has also been detected in Windsor, Ontario of Canada and a small portion of Lucas County, Ohio. What symptoms does a tree exhibit that is infested with the borer?
Infested trees exhibit top-down dieback typical of other phloem borers such as two-lined chestnut borer. It has been observed that one-third to one-half of the branches may die in one year. Most of the canopy will be dead in two years. Affected trees may have vertical splits in the bark 2-4 inches long. Often dense sprouting of shoots can been found arising from the trunk or roots. Although difficult to see, the adult beetles make a "D"-shaped exit hole in the bark, roughly 1/16 inch in diameter. What do Emerald Ash Borers look like?
The adult beetle is dark metallic green in color, 1/2 inch in length and 1/16 inch wide.
What is the life cycle of this borer?
The beetle appears to have a one-year life cycle. Adults begin emerging in late May with peak emergence in mid-June. Egg laying occurs soon after adult emergence. After hatching, the borer goes through several larval stages, overwinters as a larva, then pupates in late spring. How is this pest spread?
The ash borer can be spread through movement of infested trees or in logs and firewood. The borer is a good flier, although it is doubtful that it can fly long distances. Most likely, spread would occur by movement of infested material and adult flight, while long distance spread would occur due to movement of infested material or other human activities. This is why it's so critical that residents, businesses and municipalities in Southeast Michigan adhere to the quarantine and do NOT move ash trees or materials, including firewood, outside of the six impacted counties. How long has the Emerald Ash Borer been in Michigan?
No one knows for sure. Experts feel that it may have been in the Detroit area as long as five years or so, based on the age of trees affected and when tree dieback was first observed. Does it only attack dying or stressed trees?
While many of the trees affected by this ash borer appear to have been stressed by drought, disease or poor soil, in many instances healthy trees were also infested and killed by the borer rather quickly, in one to three years. What are other insects may attack ash trees?
It is not uncommon for diseased or dying trees to be attacked by secondary borers once the tree is weakened. Some of the secondary pests attacking ash include larvae of various native cerambycid beetles, clearwing moths or even certain Diptera species. What can I do to protect my ash tree? Will anything kill EAB?
Unfortunately, at this time, the state and researchers have very little information about this destructive beetle from its native region and very limited control or management recommendations exist to date. Aggressive and comprehensive research projects are currently underway to learn more about this pest's biology and to develop effective management, control and eradication options. In the interim, plant health officials recommend an integrated, comprehensive approach of proper sanitation, diversity in new plantings, practicing sound tree care techniques and possibly using appropriate insecticide treatments. Before you hire a tree-care company or arborist, or purchase insecticide to treat your ash trees yourself, make sure you need to. First, homeowners need to make sure they have ash trees and not some other type of tree. Second, insecticide treatments are not likely to help dying trees with extensive dieback, more than 50 percent of the top canopy of the tree. Finally, there is no need to treat ash trees unless you live in one of the infested counties: Wayne, Oakland, Macomb, Livingston, Washtenaw and Monroe. Until research findings become available, consumers and homeowners are urged to be wary of companies promising a solution or cure to the Emerald Ash Borer. Contact your local Michigan State University Extension Office at 586-469-6440 or MSU Plant Diagnostic Services at 517-355-4536 or online at www.emeraldashborer.info for further information regarding potential treatment of this pest.
What is being done on a statewide basis about this new pest?
An Emerald Ash Borer Task Force has been formed to address this pest and develop and implement a management and eradication strategy. Task Force members include the Michigan Departments of Agriculture and Natural Resources, Michigan State University, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service and Forest Service, in cooperation with local units of government and various industry groups, associations and universities. Who do I call to get more information on the Emerald Ash Borer or to report an infested tree?
Contact local offices of the Michigan Department of Agriculture, Michigan State University Extension Extension at 586-469-6440 or the Michigan Department of Natural Resources. You may also contact the Emerald Ash Borer Hotline toll-free at 1-866-325-0023 or visit the state's Emerald Ash Borer web site at www.michigan.gov/mda using the key word - ash borer.
Do you have a question that is not listed?
Call us at (586) 469-6440.
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