Professional Guide to Emerald Ash Borer Insecticide Treatments

Revised: 
5/13/2014
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).  Based on current research, treatments are suggested only for ash trees located within 15 miles of a confirmed EAB site, or for trees located within a quarantined area.  Insecticide treatments are not recommended for ash trees located outside of these areas.  Even within the 15 mile radius, not all trees should be treated.  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)
• 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 up to 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

Product

Active Ingredient

Timing

Application Method

Tree-äge

Emamectin benzoate

April to September

Trunk injection, Arborjet

Treeazin

Azadirachtin

Early/mid-April to
early September

Trunk Injection; Ecoject

ACE-Jet

Acephate

Mid-May to mid-June

Trunk Injection; Arborjet

Acecap Implants

Trunk Implant

Merit
(75 WP, 75 WSP, 2F)

Xytect

 (2F, 75WSP, Infusible)

Imidacloprid

Mid-April to late-May

and/or

Early-Sept. to mid-October

Soil injection or drench

IMA-jet

Mid-April to mid-May

Trunk injection, Arborjet

Imicide

Trunk injection, Mauget

Pointer

Trunk injection, Wedgle

Inject-A-Cide B

Bidrin

Mid-April to mid-May

Trunk injection, Mauget

Safari

Dinotefuran

Late-April to late-May

Soil drench, trunk spray

Transtect

Astro

Permethrin

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

Preventative bark and foliage cover sprays

Onyx

OnyxPro

Bifenthrin

Tempo

Cyfluthrin

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 (www.emeraldashborer.info).  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.

Garden Now

Japanese beetle season is just beginning. Learn about their biology, damage, and management:
Cooperative Extension University of Wisconsin-Extension