This document discusses the emerald ash borer, an invasive wood-boring insect from Asia that has killed an estimated 250 million ash trees in the United States. It has spread to 14 states and 2 Canadian provinces, infecting over 20% of ash trees in Illinois. The larval stage tunnels through tree vascular tissue, cutting off water and nutrients. Heavily infested areas have seen ash tree regeneration cease. Integrated approaches involving insecticide treatments, biological controls, and tree removals may help manage the spread. Factors like ash population density and tree species influence management strategies.

2.  Invasive wood-boring insect
 Native to Asia/China
 Responsible for death of estimated 250 Million US ash
trees (so far)
 Current estimates-25 million (20%) dead or infested ash
in IL.
 Also found in 14 other states and 2 Canadian provinces
 In 2006 detected in Lily Lake/St. Charles, Wilmette,
Evanston, and Winnetka
 Today, there are 193 confirmed communities in IL.
 As of 2011- 22 counties confirmed in IL, 39 within
quarantine.
 Quarantine has consumed some states

6. The larval stage of the insect tunnels
through the vascular system of the tree,
cutting off the water and nutrient supply
to the tree.

13.  Roughly 20% of the
greater Chicago land
urban trees are ASH.
 Very popular replant
after DED.
 Well-suited street tree.
 Some municipalities as
high as 40%.
 Some subdivisions as
high as 90%.

14.  May not be evident for
2-3 years. Early
detection is very
difficult!
-Initially attacks along upper trunk
and branches - canopy die back.
-Succeeding attacks found on main
trunk and root flares (much later).
-Trees may lose up to 50% of canopy
in first few years, die within 5-7
years.
-”50% threshold”
-Exponential death curve.

15.  Tree trying to re-sprout
from below injury
points

16.  Woodpeckers
may create
holes trying to
get to the larvae

17. Bark splits
Larval activity
creates gaps in the
tissue and prevents
moisture flow,
resulting in
cavitations and
linear fissures,
sometimes exposing
the galleries
underneath.

19. And how we can use it to our advantage.

20.  Survival analysis shows areas with high ash density
die slower, K.Knight, USDA Forest Service, Delaware,
OH
 What does this mean? Why?
 Areas high in ash density tend to see the individual
trees die over a longer period of time.
 Simply put, more trees to chose from, and overtake.
 Municipalities with high ash populations MAY have
“more time” for a management plan.
 Residents in these area MAY have “more time” too.
 Unfortunately, the opposite applies for few ash.

21.  The Rise and Fall of EAB population and the Ash
Overstory at Three Stages of the Invasion Wave, S.
Burr, MSU, E. Lansing, MI
 EAB populations are a classic bio-bell curve.
 Cusp(leading edge) has low but building populations.
 Crest has massive populations
 Core(after the “wave”) has low but lingering
populations.
 If cost and impact can be minimized during the Crest
by proactive actions, overall impact may be
minimized.

22.  Direct and Indirect Ecological Impact of EAB in
Forests of SE Michigan, D. Herms, OARDC, Ohio
State University, Wooster, OH
 Ash regenerate quickly (in the Core), but once they
become large enough to host EAB lifecycles, they are
infested.
 This results in ash mortality before tree maturation.
 Trees are overtaken before they can produce seeds.
 Soil seed banks are empty in heavily infested areas.
 Ash regeneration has ceased.

23.  An Overview of EAB Host Resistance Research at
Ohio State University since 2003, D. Herms, OARDC,
Ohio State University, Wooster, OH
 EAB has a preference of our native ash.
 Black and Green most preferred.
 White seems to “resist” for 2-3 years.
 Blue for a bit longer than White.
 Can use this natural tolerance/resistance to our
advantage by focusing treatments on these.

24.  Chemical (systemic insecticides)-limited
 -”over the counter” for homeowner
 - licensed applications
 Biological control (parasitic wasps)-limited
 -larval parasites
 -egg parasite
 Aggressive removals of infested trees; reduce ash population, host
material, potential beetle pressure.
 Removal of confirmable trees and continued monitoring of ash
population health.
 Most often a combination or an integrated approach.

28.  Do your homework
 Consult an arborist
 Respect decisions made by others, their situation may be
different than yours.
 Get quotes from several tree care companies
 Consider the costs of:
 inaction
 removal
 pesticide treatment
 maintenance
 combination
 Consider the proximity of the EAB infestation
 Count your ash trees
 Alternate treatments in different areas
 Plant a variety of new tree species

29.  Strategies are typically derived from economics, and
proximity to confirmed infestations OR current
infestation status.
 Homeowners additionally consider property value,
impact on landscape appearance, heating and
cooling, sentimental value, etc.
 Municipalities also consider total number of trees
being managed, optimal diversity, staff, equipment,
contracting, etc.
 Everyone MUST consider safety and liability.

30.  What are we certain of?
 -It’s always worse than we think…
 -Trees will come down…
 What’s uncertain?
 -EAB found in US in 2002, how long had it been here?
 -EAB found in IL in 2006, how long had it been here?
 -Where else is it that we don’t know?
 -In what capacity do treatments work best?
 -How long will a treatment regiment need to last?
 -What’s working the best?
 -ETC…

33.  Questions and concerns?