TWO YEAR EAB TREATMENT CYCLE FOR HOLS ASH TREES

There is some recent research suggesting that treating EAB on a three year cycle may be possible for good insect control. While we are encouraged by these findings we have chosen a two-year cycle for HOLS ash trees. This is the time frame the arborist recommends as per their letter below and the insecticide label stating that two years is the protected period. We have adopted this rigorous and conscientious program to ensure the protection of HOLS ash trees.

We see the cost difference for the additional assurance that the trees will be protected to be reasonable. By our calculations, the difference in cost between the two year and three year cycle is an average of an additional $30 - $50 per tree on a two year cycle compared to three years. With ash trees being such a vital part of our urban canopy, we feel this is worth it to be certain they are protected. 

We continue to advocate for the city to treat the ash in 2024, as we have advocated since 2021 for them to be treated in 2022, then in 2023, without success. We are providing a convenient way for HOLS residents to protect their neighborhood trees this year, however, as it will still be under the pesticide’s protection, they will not need to be treated again until 2025.  Hopefully by then, the city will have more of a plan in place.

From Gary L. Eichen, Plant Health Care Director, SavATree, March 28, 2023

Having been involved with EAB dating back to 2002 in Metro Detroit Michigan, where I was The PHC/ Lawn Care Mgr. for Mike's Tree Surgeons in Troy, Mi. and where I am still based as Asst. Service Line Director for SavATree, I am intimately aware of trunk injections as a means of controlling many insect pests of trees.

I have performed almost 10,000 in my 35-year career. In fact, Mike's Tree Surgeons performed tree spraying and injections in the trials run by MSU in Troy, Mi. As a result of my experience, combined with my personal knowledge of EAB and the damage it is capable of, I can tell you that at this time, I would maintain a 2-year cycle on trees showing minimal injury….We firmly believe the current label that is associated with the active ingredient, emamectin benzoate, that states a 2-year rotation provides the most protection.

There is research on-going that may lead to a peer-reviewed, science-based research paper that will prove that a 3-year rotation can be done. This would entail proving that there is adequate ppm (mg/kg) in the stem tissue to not only control larvae feeding in the tree, but adults that feed on leaves, prior to egg deposition.

However, at this time neither the manufacturer of the emamectin benzoate product, nor the manufacturer of the injection system used to apply it have changed their stance on this situation. They have both maintained their current position on a 2-year cycle, so do we. In the event that the label changes, SavATree will change with it…. Feel free to contact me with any questions.  

Gary L. Eichen
Asst. Service Line Director, PHC / LawnCare, ISA Certified Arborist, SavATree LLC

Ofc. (248) 918-2452, Cell (248) 866-2584, geichen@savatree.com