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VILLAGE ASKS PROPERTY
OWNERS TO WATCH FOR
TREE-KILLING EMERALD ASH BORER, OFFERS ASSISTANCE |
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EMERALD ASH BORER UPDATE
April 25, 2008
What can fit on a penny, is bright shiny green and has already caused the death
of 20-25 million Ash trees? The Emerald Ash Borer. This destructive pest was
first found in Illinois in 2006, in Kane County. Since then it has been found in
Cook, LaSalle and DuPage counties. In response to these announcements, the
Village of Mount Prospect is again asking property owners to watch for any signs
that this highly destructive insect is present in Mount Prospect’s ash trees.
The Village is offering free educational packets that describe the pest and its
symptoms. Additionally, upon request they will inspect any suspect ash trees
within Village limits.
Since the announcement of the finds here in Cook County, the Village has been
diligently inspecting ash trees. “As far as we know, Emerald Ash Borer (EAB) is
not present in our town, but if it ever shows up here we hope to know about it
quickly so control efforts can start as soon as possible” said Forestry/Grounds
Superintendent Sandy Clark. “We’re very concerned that EAB has now been
confirmed in Illinois. Roughly 4200 of Mount Prospect’s 25,000 parkway trees
(about 1 in 6) are ash trees. Additionally, we estimate that there are likely
thousands more ash trees on private property in Mount Prospect. Ash trees have
been very widely planted in our town and in much of northeast Illinois, because
they are usually fairly inexpensive and generally quite tolerant of soils and
climate in this area.”
Clark noted that the Public Works Forestry/Grounds Division has been on the
lookout for this insect for a long time. “Since 2002,” she said, “we’ve been
watching periodic reports describing the borer’s spread across the United
States.” Clark noted that experts monitoring the spread of EAB now report that
the economic impacts have been estimated at tens of millions of dollars. In
order to increase public awareness of this problem, the Village offers the
following information:
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HOW DO I KNOW IF MY TREE IS AN ASH?
Ash trees have several green leaflets per leaf stem, usually 7. The leaflets are
located directly across from each other with one leaflet on the end. The leaf
shape is “lanceolate,” which means they are much longer than wide, broader below
the middle and tapering to the top. If the tree in question is on public
right-of-way in Mount Prospect, its species may be verified by a call to Public
Works, since all such trees have been inventoried. |
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WHERE DID EMERALD ASH BORER COME FROM?
The Emerald Ash Borer is an exotic insect pest from Asia. It was first
discovered in the U.S. in 2002 in southeast Michigan. Since that time, this tree
destroyer has also been detected in Indiana, Ohio, Maryland, Illinois,
Pennsylvania, West Virginia and Ontario, Canada.
Prior to its discovery in the U.S., the Emerald Ash Borer was found primarily in
Korea, China, Japan and other East Asian countries. In the U.S. thus far, this
pest has been known to attack all ash trees native to the U.S., specifically
White, Green and Blue ash. It does not attack Mountain ash and may not attack
European ash.
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WHAT IS THE EAB’S LIFE CYCLE?
The Emerald Ash Borer adult is a dark metallic green beetle about 1/2” in length
and 1/8” in width. Adults are usually only present from early May to late June,
when they feed on the leaves of ash trees. Soon after they emerge, the adults
lay eggs on the trunk and branches of ash trees. After about a week the eggs
hatch into larvae which then bore into the tree. It is this larval stage that
does the major damage. Larvae are creamy white in color, can grow up to an inch
long and are found under the bark of the trees. These larvae tunnel and feed,
creating S-shaped galleries. This tunneling cuts off the food and water supply
to the tree, causing it to die. Later in the year, the larvae pupate and
overwinter under the bark. New adults emerge the following year, beginning
around May1st. Their emergence holes are very small (only 1/8”) D-shaped holes
and can occur just about anywhere throughout the tree.
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WHAT ARE THE SYMPTOMS?
Infestation by EAB can be very difficult to detect until the branches of the
tree start to die. Usually the leaves on the upper third of a tree will start to
thin, and the branches will begin to die back. This is usually followed by a
large number of shoots or branches arising below the dead portions of the trunk.
Additional evidence of infestation includes the tiny D-shaped exit holes on the
branches and the trunk. Distinct S-shaped larval feeding tunnels may also be
apparent under the bark. Woodpecker damage, including large holes and whitish
patches on bark, may become evident since they feed on the larvae under the
bark. This is a very good indicator that EAB larvae are present in the tree. |
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HOW DOES EAB SPREAD?
It is thought that the beetle arrived in the U.S. from Asia in the early 90’s,
but it was not positively identified until 2002. Experts believe that the larvae
hitched a ride across our borders traveling in wooden pallets. Once arriving in
the United States the insects emerged as adult beetles and the cycle of
devastation began. Most of the spread of EAB since then is believed to the
result of artificial movement of firewood. The beetle is also an excellent flier
and can travel fairly far distances in search of food and egg-laying sites in
ash trees. Additionally, pockets of EAB outbreaks have been linked to the
movement of ash tree nursery stock out of infested areas.
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WHO IS FIGHTING THE BEETLE?
Because this insect has such great potential to decimate both forests and urban
tree populations, national and state agencies are working together to slow the
spread of EAB. These agencies include the USDA Forest Service, APHIS (Animal and
Plant Health Inspection Service), and the various state Departments of
Agriculture. In Illinois the lead agency is the Illinois Department of
Agriculture (IDOA) (1-800-641-3934).
Fortunately in Illinois, a wide variety of organizations and agencies concerned
about our urban and forest trees have had an “Illinois Emerald Ash Borer
Readiness Plan” in place since 2004. This plan was compiled by a committee led
by the Morton Arboretum’s Community Trees Advocate and it outlines a coordinated
and prompt response by all involved parties.
Currently the IDOA is promoting a “Slow the Spread” approach to EAB in Illinois.
This was adopted after other states had little success with complete
eradication. (In Michigan and some other states, eradication policies meant
removal of even healthy ashes within ˝ mile of confirmed finds, after EAB was
first found.) In Illinois, this approach was never promoted. In 2007 the
Illinois Department of Agriculture conducted a limited one time tree removal
program of only infested and symptomatic trees within a ˝ mile of previously
confirmed finds. State employees continued to survey trees throughout Illinois
to confirm how far the EAB had spread. Selected trees were cut down and their
bark was peeled to check for the presence of the EAB larvae.
In 2008 the IDOA, in conjunction with APHIS, plans to begin a new survey
process. The new plan will include the use of purple traps to monitor the spread
of EAB. These traps have been found to be highly effective in detecting EAB when
baited with an attractant called Minuka oil. These traps will be placed in a 100
mile band, spanning the outermost known EAB infestations. Additionally, some
traps will be placed throughout the metro Chicago area and parts of southern
Illinois. This surveying technique will be used while the adult beetles are
present, roughly May through August.
Currently there are two levels of quarantines in Illinois. A federal quarantine
prohibits the movement of firewood into and out of Illinois and a state
quarantine prohibits the movement of any ash material out of the Kane County and
Cook County infested areas. (As of April 27, 2007 Mount Prospect was considered
to be in a state-quarantined area, even though the insects have not yet been
found within Village limits). Additionally, the IDOA is requiring anyone who may
work with ash wood or debris in or around the quarantined areas to sign a
Compliance Agreement. Essentially, the agreement states that ash debris will be
handled properly. This means it must either be processed to a degree where it
can no longer harbor the insect, or it must be taken to a certified processing
center that will process it. Please see the IDOA’s website,
www.illinoiseab.com, for more
information about current quarantines and compliance agreements.
WHAT HAS MOUNT PROSPECT DONE TO PREPARE?
Since 2003, the Village of Mount Prospect has taken numerous steps to educate
the public. We’ve issued multiple news releases, aired EAB information on an
episode of “Talk of the Town”, displayed and distributed information at the
Public Works Open Houses, mailed to all property owners adjacent to Village ash
trees a postcard describing what to look for, and provided our staff with EAB-specific
training.
Since the fall of 2006, the Village has worked each year with members of the
Morton Arboretum on a bark peeling and trap tree project. A small number of ash
trees that were declining or growing in inappropriate sites (such as beneath
power lines) were cut down. Then the bark was scraped off to see if any EAB
larvae were in the trees. Additionally, Village crews began routinely stripping
bark of all ash trees that are removed for any reason and will continue to do
so.
In the fall of 2007, the Village conducted an insecticide trial program. The
Village selected and treated approximately 130 ash trees in public locations.
All of the trees treated were less than 15” in diameter and either white or blue
ash. (Research has shown that smaller trees may respond to the treatments better
than large trees and that white and blue ash show a little more resistance to
EAB than green ash. Also, the Village’s white ashes in general are in better
condition than the green ashes.)
Beginning in 2008, the Village plans to begin an ash reduction program. Ash
trees that have had a history of limb failure are in poor condition or are
growing beneath power lines may be removed by the Village this fall. The trees
to be removed have not yet been selected, and adjacent property owners will be
notified in advance. This will be part of an ongoing process for the next few
years. The intent of this program will be to start spreading the removals out
over many years, instead of having to deal with removing hundreds, if not
thousands of infested trees all at once. The reduction plan will also help to
get the Village’s ash tree population down to a smaller size which is healthier
for the urban forest. The Village also plans to continue working with the Morton
Arboretum on their trap tree survey and to participate in the new survey process
by placing and monitoring purple traps.
To be in compliance with the IDOA, Mount Prospect has signed the Compliance
Agreement and is requiring all tree care companies who work for the Village to
do so also.
Also, Village staff members are actively participating in the Northwest
Municipal Conference’s “Best Practices Committee” and the “Municipal EAB Team”,
in order to promote a regional approach to the EAB battle.
ARE THERE ANY NATURAL PREDATORS OR CHEMICAL TREATMENTS THAT ARE EFFECTIVE ON
EAB?
EAB is native to China, and there are no known natural predators here in the
United States. It should be noted that certain parasitic insects and fungi,
predaceous beetles and woodpeckers have all been found to attack EAB in
Michigan. However, these agents alone are not able to control EAB at current
populations.
Since EAB was identified in the U.S., scientists have been looking for a
biological control from its native region. There is hope on the horizon for
developing the use of a natural pest, with the findings of three tiny parasitic
wasps, in China. In 2007, after a period of monitoring in a lab, some of these
wasps were released in central and southeastern Michigan. These releases will be
monitored over time to see how the insects establish themselves. Additional
research is ongoing to determine future release sites.
Currently, insecticide treatments are being researched. Both soil injections and
trunk injections are being used in an attempt to control larvae. Currently state
and federal experts do not recommend the use of insecticides, but some products
have shown promise when used preventively on healthy ash trees. As of April 15,
2008 a new product known as Tree-Age seemed to show the greatest promise for
preventative use. More information about the use of insecticides can be found at
www.illinoiseab.com,
www.pestid.msu.edu and
www.emeraldashborer.info.
HOW CAN I HELP?
The Public Works Forestry/Grounds Division believes that public education about
EAB offers the best hope for both preventing its spread to our town, as well as
detecting it early if it does arrive here. We are asking property owners to…
- HELP MONITOR AND REPORT- Learn about EAB, check your ash trees
for the pest and call us at (847) 870-5640 if you believe you have found
either the insect or an infested ash tree. We’ll try to respond promptly to
all such calls.
- REFUSE TO MOVE FIREWOOD- Use only local firewood (even when
traveling), and burn the wood on site or leave it when you move on.
Especially, don’t bring firewood or logs from other states, or any areas
that may become quarantined in Illinois, to Mount Prospect. Before flight
season (May 1st) burn your current stock of firewood if it may contain ash
wood.
- CARE FOR ASH TREES- Call Public Works if a public ash tree seems
sick or needs maintenance. Care for private trees routinely, using
ISA-certified arborists when hiring tree care companies.
- PLANT FOR DIVERSITY- Don’t plant ash trees; consider using
underutilized tree species instead.
- STAY INFORMED-Check for periodic updates at these websites:
www.mountprospect.org,
www.illinoiseab.com, and
www.emeraldashborer.info.
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