Emerald Ash Borer - Emamectin Benzoate

Emamectin Benzoate

Emamectin benzoate (trade name Tree-age) is applied through holes that are drilled into the ash trunk. An average 20" diameter tree requires 6 holes. Each hole has a plug that is designed to prevent the solution from coming back out and to create a reservoir from which the solution is absorbed by the tree. This product is the most toxic to the insect and had the highest score in terms of having the least amount of living larvae in treated trees. Only professional and licensed certified applicators can apply this product.

The Positive Aspects of Emamectin Benzoate are:

• It is directly injected into the tree. Can be used in environmentally sensitive areas.
• It lasts for 2 years. In 2009, City of Chicago started experiment with higher dose 3 year applications.
• Strongest protection
• Is the best rescue treatment.
• A Larvaside that has an effect on all stages of Borers.

Downsides of Emamectin Benzoate

• Holes must be drilled into the tree every two years. Ash are tough, and could be treated a few times without issue, but over many years drilling and chemical wounds will compromise the trees health.

• It can only be applied by a professional. Homeowners or do-it-yourself people cannot use this product as it is a restricted use material.
• Plugs needed for the injection holes are required and cost 0.50 each.

Cost of Emamectin Benzoate

• Milwaukee - which is the single largest user claims it costs them $45 per year per tree to treat (2 year treatment). Their average ash size is 16" diameter. They provide their own labor.
• Other cities with fewer trees can expect to pay about 10% - 30% more.
• Bids in The Chicago metro area for city contracts have been going for as Low as $5 – $9 an inch depending on number of trees.
• The average time in man hours to inject one tree averages between 25 minutes and 1 hour.
• The average homeowner will pay between $7 – $15 per diameter inch, typically larger trees and multiple trees cost less per inch.