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I live in KC and we are just in the beginning of our EAB journey.  Like many metros, our urban tree canopy is overloaded with ash.  Some suburbs have documented 1/4 of all street trees are ash.

I have been searching for good data that really shows how well the treatments are going in heavily infested areas.  It seems most studies I have found were funded by an "interested party" in selling or applying the chemicals to treat EAB.  So I am going into the trenches to ask you: the seasoned arborist with several years fighting (or getting run over by) EAB.

My question: Are there studies showing multiple year success of treatment when EAB came in and destroyed all untreated trees?  Is success “fair”, “good” or “excellent”?  Have you done your own study?  Will these treated ash be weakened over time from all the small damage created by so many young larvae that do a tiny bit of damage before they die during the massive swarm when the EAB population swells?  Can I expect a treated tree to flourish when the EAB outbreak is full-on?  Will the lone treated ash in a sea of untreated ash pull thru with flying colors?

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  • My name is Wayne White, BCMA employed by Emerald Tree Care LLC.  I have successfully treated ash trees since 2002 and treat in five states.  I maintain that I have personally treated more ash trees since 2002 and have more alive today as a result than ANY other arborist in America.  Pretty bold statement but I am still waiting for anyone to offer data to the contrary.  My website has been promoting treatment of ash for ten years now.  The website many of you have mentioned actually features me in Chapter 8 - The airport study.  Dr Dave Roberts, who discovered this insect in 2002, knows me and my success stories very well having reviewed many of my early sites that are still alive today. Those trees at that airport are still flourishing today and NONE have ever died from EAB.  Detailed studies in the cities I treat in have been going on yearly.  I have been treating West Chicago, Il (1,800 ash trees) and Roselle, IL (800 ash trees) since 2011.  West Chicago was heavily infested when we started treatment and they expected a 30% failure.  Current data shows less than 5%.  Roselle lost 6 trees the first year after treatment and have lost NONE since!  They only treated about 1/3 of their city ash population in order to bring their numbers back in line to proper inventory levels.  Even though they were able to prove that they could treat for 7 years for 1/2 of the cost of removal (no replacement tree) they nevertheless decided their overall ash population was too high at over 20%.  Last year 300 of the dying, untreated ash were removed at a cost of 3 times the yearly treatment contract for ALL of their ash trees.  I also have treated Downers Grove, Il for 4 years and they just awarded me the next three years.  Mokena, Il started last year and Cedarburg, WI has been under treatment since 2009.  Contact any of these city foresters for a referral, or contact me and I will give you how to contact them.

    I use imidicloprid in the soil as well as injection with ArborSystems Direct inject system.  NO DRILLING!  I will not compromise the underlying science proven by Dr Alex Shigo that ring porous trees should NEVER be drilled for ANY reason.  Northbrook Illinois is no longer drilling their elm trees for DED treatment.  They awarded me the contract this last year to use the portle needle from ArborSystems instead.  The reason they don't drill anymore is due to the massive decline of their elms clearly from the repeated damage of drilling every three years since 2000.

    In addition to Imidicloprid to protect my ash trees, all ash trees are fertilized and a bio-root stimulant called Essential is added with the soil imidicloprid treatment.  The EAB takes two years to complete it's life cycle when battling healthy ash trees.  Keep them healthy and treated and the success rate skyrockets.  In addition I can easily say that I expect my ash trees to look 120-130% as good as the year we started treating them.  They are indeed flourishing amongst the dying untreated ash.


    You CAN save ash trees!  It costs less than removal!  Prevention is the key!  DO NOT DRILL YOUR TREES TO TREAT THEM!  Don't wait until it is too late.  I have helped other arborists all through the country get started in their areas.  Nice to hear you are in Kansas City as I have been in contact with an arborist there for three years now and he has decided to treat exactly the same way do!


    TOGETHER WE CAN MAKE A DIFFERENCE!  Feel free to email me at and visit my website at

  • David, I know it will be a face-palm moment, but who is MPB?

    David Merriman said:

    We welcomed the positive data for EAB treatments after working with a tougher insect, MPB. We were surprised and encouraged that trees could be helped even after EAB is in the tree. That said we are in wait-and see mode after doing a soil injection with Merit this fall.



  • We welcomed the positive data for EAB treatments after working with a tougher insect, MPB. We were surprised and encouraged that trees could be helped even after EAB is in the tree. That said we are in wait-and see mode after doing a soil injection with Merit this fall.

    One thing about TREE-age is that it's efficacy can be degraded if clear-winged ash borer is also present in the tree. Here in Denver we have a lot of that so our EAB treatments left out TREE-Age for the time being.  Finally although the official discovery for Colorado was 10/31/2013, since then lots of unofficial data seems to indicate that it's likely been around at least three years or even longer. So we are recommending treatment before the presence of the EAB is in the tree. It's a balancing act for sure.

  • I work for a tree company in Chicagoland. We having been treating for EAB preventatively since 2006. All the trees that have been continued to be treated are still alive. We started using imidacloprid and have moved on to Tree-Age. We made this change only because Tree-Age was getting all the press and customers wanted the treatment that lasted two years. As far as we can tell, imidacloprid works just fine.

    Now(2013) we are getting into the stage where new customers have trees that are infested to some degree but they still want to treat. We treat these trees with the disclaimer that they might not survive. It will be interesting to see how many do make it.

    I recommend you take a look at   This is a website that has info from Dr. Dave Roberts of Michigan State U. They have case studies where they successfully treated some of the first infestations of EAB in the U.S. I know there is debate as to who discovered EAB, etc. etc. which I will not get into. There are also people who take Dr. Deb McCullough's research with a grain of salt(do people still use that expression?). As a working arborist, I just want to use what works. One thing about the Michigan State cases is that they also used mycorrhizae and fertilization in bringing the trees back to health.

    My overall advice is to start treating trees before they show signs of EAB. Something we found out in Illinois is that the trees can be infested for 3-6 years before you see any signs or symptoms.

  • Nick, Thanks for your good thoughts on this.

  • To add to this... chemical usage results have been very good in actual city usage.  The local city forester should work out timing for insect life cycle and tree translocation, make good tree selections on what to keep and treat and what should go, and that increases the long term survival of trees and make them thrive.  

  • I think many cities are using chemicals to prevent prevent infestation or conserve portions of their ash urban forest.  You aren't seeing research projects on it because cities don't fund research and college research is funded by chemical companies. I would love it if non-interested parties funded research but that doesn't happen in any industry.   Ask chemical suppliers for a list of clients if you want the whole list but I know Oakville, ON, Milwaukee, WI, and others in those states/province as well others in Ohio, Illinois, Minnesota, and others are all actively managing ash to conserve canopy or extend lifespans of the ash urban forest using preventative and post-infestation chemical application.  

    If you get to the tree while infestation is very low or before infestation.. .then all research and those I have talked to say it works. I can tell you that Oakville, ON has 99% efficacy to date.  I think if the chemicals didn't work very well... that would be a clear and public message to us and chemical suppliers from home and city tree owners.  However... I do trust the research numbers on success rates when I also factor normal urban impacts on health of trees.  A tree weakened by mower damage, poor soil, and bad pruning ( just a few examples of urban stress) will not translocate chemical well leading to a tree that may get infested. There has been research showing infested trees have a lack of continuous pathways and that prevents chemical reaching entire canopy.

    Look up, or research from Michigan (Dr. McCullough) or this link for the best summary

    Will continued impact from larvae weaken tree? Any continued impact will impact tree health but I am not aware of studies measuring this.  There is research showing that a heavily infested 20" tree can have a >99% reduction in live larvae with emamectin benzoate and no re-infestation after 2 years.

    Will the lone tree flourish while all others are dying? That is dependent on the arborist managing the tree and the methods used to manage the urban forest.  Not allowing trees to just die while standing and increase the local insect population will keep numbers at manageable levels... plus standard good tree care practices can keep any tree flourishing while others are left alone.  If all you do is treat and ignore all other aspects of tree care, I would not give you as good odds, but would still bet on survival and normal growth.

    KC is getting a great start to managing this problem.  Selective removals, treatment on desirable trees, and monitoring of ash population.  This community started with the right info ( an inventory), their forester checked with experts from other cities, Dept of Conservation, chemical suppliers, and researchers... and developed a response plan.  They can now monitor and adapt as they learn more.

  • I would check out  The resources on that website should give you many of the answers.  In my jurisdiction we are awaiting the onslaught of EAB. It has been detected and now its a matter of dealing with it.  Treatment seems to be a good strategy as it postpones some of the mortality  I think success will be measured by how overwhelmed one becomes when the infestation approaches its' peak.  

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