Invasive wood-boring insectNative 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 WinnetkaToday, there are 193 confirmed communities in IL.As of 2011- 22 counties confirmed in IL, 39 within

quarantine.Quarantine has consumed some states

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

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%.

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.

Tree trying to re-sprout from below injury points

Woodpeckers may create holes trying to get to the larvae

Bark splits

Larval activity

creates gaps in

the tissue and

prevents moisture

flow, resulting in

cavitations and

linear fissures,

sometimes

exposing the

galleries

underneath.

And how we can use it to our advantage.

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.

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 populationsCore(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.

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.

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.

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.

Do your homeworkConsult an arboristRespect decisions made by others, their situation may

be different than yours.Get quotes from several tree care companiesConsider the costs of:

inaction removal pesticide treatment maintenance combination

Consider the proximity of the EAB infestationCount your ash treesAlternate treatments in different areasPlant a variety of new tree species

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.

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…

Questions and concerns?