Boards & Commissions Supporting Documents - 07/02/2008 - Board of TrusteesITEM 10.1).- - -�
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VILLAGE OF OAK BROOK
Interoffice Memorandum
DATE: 7/2/08
MEMO TO: David Niemeyer, Village Manager
FROM: Michael J. Meranda, Public Works Director
SUBJECT: Emerald Ash Borer & Gypsy Moth Update
The intent of the following is to provide you and the Village Board with some basic information
on two potentially troublesome forestry related issues that need discussion and perhaps consensus
on how best to move forward. Though independent of one another, they can be easily bundled
together for more efficient management and resource allocation.
Emerald Ash Borer
With the recent discovery of the emerald ash borer in the City of Chicago as well as a few
suburbs - Wilmette, Naperville, St. Charles to name a few - it probably is only a matter of time
(if not already here), before the borer is detected in Oak Brook'. To summarize numerous recent
newspaper articles related to the ash borer, the bottom line is that they project a grave danger to
our ash population, both public and private. The ash borer larvae accomplish this mast
destruction by burrowing into the bark of the tree and carving a series of serpentine channels
through the tree's circulatory system. These channels interrupt the trees' ability to draw water
and nutrients up the trunk, and in time, the tree dies. This is only complicated further as the borer
has few natural predators and the few pesticides that have been developed to date, have to be
applied annually at a cost of approximately $200 per tree per injection. With nearly a 1,000
public ash trees alone, treatment simply might be cost - prohibited.
Gypsy Moths
Though not uncommon to Oak Brook, (we, as well as homeowners, have observed them for
years), the recent gypsy moth concern2 has been kept in check in recent years by the Illinois
Department of Agriculture's (IDOA) surveillance and treatment program.
1 Davey Tree, the tree service company that presently provides our tree pruning services and probably provides the
same services to 50% or more of Oak Brook residents, has been directed, for some time now, to keep alert for the
ash borer or any other invasive pest or disease(s).
Z We have had numerous reports and conversations from residents, and a few association presidents, regarding the
sighting of gypsy moth caterpillars.
INZ
Emerald Ash Borer /Gypsy Moth Update
Page 2.
Unfortunately, with IDOA moving their "Slow- the - Spread "3 program out of DuPage and into
Will County, we, and other entities around us, are on our own to develop and implement a
management /action plan to replace their efforts. At the risk of sounding like an alarmist, the
ramifications of doing nothing could become disastrous.
Unlike the ash borer, the Gypsy Moth caterpillar does damage by being an extremely ravenous
feeder that prefers Oak leaves (it will and does consume other species) and can devour up to one
square foot of leaves per day. Left unattended, (the gypsy moth too, has few natural predators)
they can inhabit an oak tree, or a grove of oaks, and in short order, completely defoliate the
tree(s) leaving it susceptible to other insects and diseases - even a healthy oak can only withstand
a few seasonal defoliations before succumbing. In spite of the fact that gypsy moths cannot be
eradicated, preventative control methods, such as aerial treatments with BT4, are very effective in
keeping the moth population in control and mitigating tree damage and eventual loss.
Summary
In summary, it is extremely important that we direct our attention to these issues as soon as
possible 'and investigate options for a managed approach to mitigate these and any future
concerns that might impact our tree population, private as well as public. As the current Public
Works Department is ill- equipped both technically and operationally to address these issues, one
thought would be to hire, through a contractual arrangement perhaps, a competent foresters who
could be charged with some, if not all, of the following:
• Conduct a Village -wide general survey, noting boundaries and adjacent stands of
trees /forests and how one infected might impact another stand in close proximity.
• Begin steps to implement a parkway tree inventory to quantify our forestry assets.
Obviously this would assist in developing costs for whatever programs or tactics are
employed.6
• Identify existing problem areas (infestations) and offer a course of proactive steps for
consideration - ie surveillance traps, aerial /ground treatments, public education.
3 "Slow- the - Spread" is a slogan that the Illinois Department of Agriculture uses to identify their program of Gypsy
Moth abatement; a slogan that correctly depicts a program geared to slow -down the affects of the infestations, not to
fully eradicate them.
4 BT (Bacillus Thuringiensis), is a naturally occurring, soil dwelling bacterium that is quite lethal once mdigested
Generally, the best time to conduct these types of treatment is in early May while the moth caterpillar is still rather
small.
5 The Morton Arboretum and the University of Illinois Extension College of Agricultural might be excellent
resources in assisting /consulting or locating management resources for hire
6 Our current Parkway Tree Inventory is 15 years old Though still useful for general purposes, it needs to be
updated in a GIS /GPS format to not only make current, but to have it conducted in a format that can easily be
revised, manipulated and queried.
Emerald Ash Borer /Gypsy Moth Update
Page 3.
• Identify, solicit and develop partnerships with other affected entities (Homeowner
Associations, Private Businesses, other Governmental Agencies, and adjacent
communities) for the purpose of information sharing, economies of scale for any area -
wide treatments, and explore /foster the possibility of cost - sharing by both public and
private entities.7
Certainly, not all encompassing, I trust the aforementioned is sufficient to jump -start a dialogue
on the subject matter.
cc: Blaine Wing, Assistant Village Manager
Doug Patchin, PW General Foreman
We have been encouraged by a few affected Homeowner Association Presidents comments that there might be a
willingness to assist in the cost. Obviously, the details would have to be worked out if in fact the Village takes the
lead in any area -wide management/treatment program