Professional Guide to Emerald Ash Borer Insecticide Treatments

Adult EAB emerges from the inner bark of an ash tree from late May till September, creating a D-shaped exit hole.

Adult EAB emerges from the inner bark of an ash tree from late May till September, creating a D-shaped exit hole.

R. Chris Williamson, UW Entomology
Revised:  4/23/2015
Item number:  XHT1185

Emerald ash borer insecticide treatment considerations.  A variety of insecticide products and application methods are available to professionals for control of the emerald ash borer (EAB). Since the presence and infestation level of EAB is quite difficult to determine at early stages of an infestation, insecticide treatments may be merited to mitigate damage by EAB. However, not all ash trees should be treated as some may be too extensively compromised or in poor condition to receive treatment. Due to the expense of yearly insecticide treatments, one should consider the value of a particular ash tree in relation to insecticide treatment costs before making any treatments. In addition, consider the health of each tree before treating. Research suggests that insecticide treatments are significantly more effective on EAB-infested ash trees with less than 50% canopy thinning. Insecticide treatments are not suggested for trees with greater than 50% canopy thinning. Ash trees with greater than 50% canopy thinning should be removed and destroyed in accordance with established state and federal guidelines. For additional information on this topic, see University of Wisconsin Garden Pest Alert XHT1215 “Is My Ash Tree Worth Treating for Emerald Ash Borer”.

Emerald ash borer insecticide treatment options.  Insecticide products that are available for use by professionals, with information on appropriate application methods and application timings, are summarized in Table 1.  These products include:

  • Ace-Jet (acephate)
  • ACECAP Systemic Insecticide Tree Implants (acephate)
  • Astro (permethrin)
  • IMA-jet (imidacloprid)
  • Imicide (imidacloprid)
  • Inject-A-Cide B (bidrin)
  • Merit (imidacloprid)
  • Onyx, OnyxPro (bifenthrin)
  • Pointer (imidacloprid)
  • Safari (dinotefuran)
  • Tempo (cyfluthrin)
  • Transtect (dinotefuran)
  • Tree-äge (emamectin benzoate)
  • AborMectin (emamectin benzoate)
  • Treeazin (azadirachtin)
  • Xytect (imidacloprid)

University research indicates that soil drenches or injections of imidacloprid provide excellent EAB protection for small ash trees [less than six inches diameter at breast height (DBH)] in the first year following treatment. Larger trees may require two consecutive years of treatment before they are effectively protected. Thus, treatment of large trees should begin before the trees become infested. While spring and/or fall applications are allowed on certain product labels, recent university research has indicated that spring applications have been more effective at controlling EAB and protecting canopy health. Most insecticide treatments must be repeated each year. However university research suggests that Tree-äge may provide more than three years of control with a single application when used at the highest labeled rate.

Trunk injections and implants require physically drilling or coring into a tree during the application of the insecticide. Thus, use of these application methods has the potential to cause injury to trees (especially smaller trees), and may provide entry points for certain disease-causing fungi [e.g., Nectria, the cause of Nectria canker (see University of Wisconsin Garden Facts XHT1094 “Nectria Canker”)].

Table 1.  EAB insecticide treatments available to professionals


Active Ingredient


Application Method


Emamectin benzoate

April to September

Trunk injection, Arborjet


Emamectin benzoate

April to September

Trunk injection, Rotam



Early/mid-April to
early September

Trunk Injection; Ecoject



Mid-May to mid-June

Trunk Injection; Arborjet

Acecap Implants

Trunk Implant

(75 WP, 75 WSP, 2F)


 (2F, 75WSP, Infusible)


Mid-April to late-May


Early-Sept. to mid-October

Soil injection or drench


Mid-April to mid-May

Trunk injection, Arborjet


Trunk injection, Mauget


Trunk injection, Wedgle

Inject-A-Cide B


Mid-April to mid-May

Trunk injection, Mauget



Late-April to late-May

Soil drench, trunk spray




Two applications at four week intervals with the first application when black locust is blooming

Preventative bark and foliage cover sprays







The University of Wisconsin does not endorse any one specific commercially available insecticide.  Products discussed in this fact sheet have been evaluated in a variety of university research tests on EAB (  No matter which insecticide you use, always read and follow all label instructions.  Avoid skin contact with insecticides and safely store insecticides out of the reach of children.

University of Wisconsin-Extension