Insect
and Disease Fact Sheet Compliments of New Century
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Emerald Ash Borer
A new
exotic insect was detected in six Southeast Michigan counties -- Livingston,
Macomb, Monroe, Oakland, Washtenaw and Wayne -- in the summer of 2002. This
pest, known as the Emerald Ash Borer, is an invasive species originally from
Asia and previously unknown in North America that affects ash trees. It has
also been detected in Windsor, Ontario of Canada. To date, it has killed or
damaged millions of ash trees in these affected areas.
|
Identification, Appearance
& Symptoms The
Emerald Ash Borer belongs to a group of insects known as metallic wood-boring
beetles. Adults are dark metallic green in color, 1/2 inch in length and 1/16
inch wide, and are only present from mid May until late July (Figure 2a &
2b). Larvae are creamy white in color (Figure 1) and are found under the
bark. The
borer's host range is limited to species of ash trees (identified by their
distinctive leaves, which are located directly across from each other on the
leaf stem and bark. In Michigan, most ash trees are white, black or green.
Emerald Ash Borer does not attack mountain ash, which is not related to
white, black, or green ash trees. |
Figure 1. Larva stage |
|
Figure 2a. Adult Emerald Ash
Borer (top view) |
Figure 2b. Adult Emerald Ash
Borer (side view) |
Usually
their presence goes undetected until the trees show symptoms of infestation typically
the upper third of a tree will die back first, followed by the rest the next
year. This is often followed by a large number of shoots or sprouts arising
below the dead portions of the trunk.
The
adult beetles typically make a D-shaped (Figure 3) exit hole when they emerge.
Tissue produced by the tree in response to larval feeding may also cause
vertical splits to occur in the bark. Distinct S-shaped tunnels (Figure 3) may
also be apparent under the bark.
Preventing the Spread of Emerald
Ash Borer
Since
this pest is highly destructive, the Michigan Department of Agriculture placed a quarantine on all ash trees and ash wood products,
including firewood, in the affected counties to prevent and control its spread.
Under this quarantine, it is illegal to move ash trees, branches, lumber,
firewood and wood chips larger than one inch in diameter outside: these six
counties. The quarantine provides the conditions for movement of regulated
articles; however, there are currently few options available to certify ash for
movement outside of the affected areas. At this time treatment options for ash
logs and lumber include fumigation or kiln drying only. Additional treatments
may be permitted once we have evidence of their effectiveness.
Not
moving firewood out of the affected counties is particularly key to preventing
this pest's spread. While firewood may- appear healthy and not visibly
infested, it may carry the Emerald Ash Borer larvae in its dormant stage. Don't
further the spread of Emerald Ash Borer by moving ash trees and products
outside of these affected counties or by taking firewood on vacation with you.
Imagine how your neighborhood or favorite vacation spot would look with some or
all of the ash trees gone. Anyone who realizes they have inadvertently moved
firewood out of this area, is advised to burn it completely properly and report
it via the state's toll-free Emerald Ash Borer hotline (1-866-325-0023)
Additionally, if you don't know what type of firewood it is, please don't move
it. It is vitally important that all Southeast Michigan cooperate and adhere to
this quarantine to help limit the spread of this new ash tree pest.
|
Figure 3. Emerald Ash Borer
damage on tree. |
Michigan
also has an active Emerald Ash Borer Task Force in place working to control and
eradicate this new exotic pest and minimize its damage. Members include MDA, the Michigan Department
of Natural Resources, Michigan State University (MSU), and 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.
Treatment & Control Options
Very
little information on the beetle is available from its native region, and
limited control or management recommendations exist to date. To help
effectively control and eradicate the Emerald Ash Borer and the threat it poses
to Michigan and North America ash resources, aggressive and comprehensive research
projects and efforts, spearheaded by MSU, are currently underway to learn more
about this pest's biology and develop appropriate 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. Until the
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 MSU Extension office for further information, recommendations and one-on-one
technical assistance regarding potential treatment of this pest.
Successful
eradication of the Emerald Ash Borer and controlling and minimizing the damage
this pest can cause requires the coordination of federal, state, local and
university efforts and resources, along with cooperation of all Michigan
residents.
Information obtained from MSU
Copyright © 2001-2003 State
of Michigan
Insect
and Disease Fact Sheet Compliments of New Century
1-877-79TREES