Treatment Options for Emerald Ash Borer Dr. Mark Shour

PM 2084 Revised February 2015 Recommended insecticides work best as preventive treatments for healthy ash trees Healthy trees have full crowns, elongating branches, and bark tightly held to trunk/branches

Preventive treatment Candidate ash trees are those planted along streets, in yard, or park settings Treatment is not practical or cost effective for woodlot trees where timber production is the primary goal

Other control considerations… 1.Identify the target tree as ash 2.Set sentiment aside, then: a.Judge health of tree b.Assess landscape value c.Determine cost/treatment X several years 3.Insecticide use for several years (yearly or every other year)

National Tree Benefit Calculator Benefits include helping clean the air, slow stormwater runoff, raise property values, sequester carbon, and reduce energy costs A 25” white ash tree has an estimated annual economic benefit of $359 in Des Moines, Iowa

Purdue Cost Calculator To run the calculator you will need : –an inventory of the number and size of ash trees –an estimate of costs for removing and treating trees based on the size of each tree. –an estimate of costs for replacing each ash tree that is removed. 3 options: treat, remove, replace

Other control considerations… 4.Preventive treatments most effective curative application may work if less than 30% canopy dieback dead branches should be removed

Other control considerations… 5.Ash trees within 15 miles of a confirmed EAB site are at risk of attack; treatments are suggested –Keep checking trees for symptoms outside of risk zone

EAB chemical control Systemic insecticides require time and active tree growth prior to adult EAB activity: –Soil treatments 4-8 weeks –Trunk injections 2-4 weeks –Some products penetrate faster

Homeowner treatment options Type of application ActiveIngredient Tree Size Trunk circumference 4.5ft -dbh) Time of Application Soil drenchImidacloprid (1.47%) Up to 60” (20” dbh) Mid-April to mid-May or Early Aug to mid-Sept Soil drenchImidacloprid (21.4%) Up to 60” (20” dbh) Early Aug to mid-Sept Soil drenchImidacloprid, Clothianidin Up to 60” (20” dbh) Mid-April to mid-May or Early Aug to mid-Sept GranularDinotefuran (2%) Up to 36” (12” dbh) Mid-April to mid-May GranularImidacloprid, Clothianidin Up to 36” (12” dbh) Mid-April to mid-May GranularImidaclopridUp to 36” (12” dbh) Mid-April to mid-May

Homeowner treatment notes Carefully read the product label before purchase & use Amount of insecticide depends on tree’s circumference If label lists spring & fall as possible treatment times, homeowners can only treat ONCE per year

Homeowner EAB control Pull back mulch 12” from base of tree Soil drench treatment: trees up to 60” circumference/20” diameter. Apply spring every year. Granular treatment: trees up to 36” circumference/12” diameter. Apply spring every year.

Homeowner treatment notes Apply soil drench product. Return mulch after product taken into soil. Don’t apply to saturated or frozen soils

Apply granular products evenly on soil around base of tree within 18” of trunk Irrigate after application to dissolve granules Reposition mulch at tree base

For larger trees… Treatment by commercial applicator –Soil injection or drench –Basal trunk spray –Trunk injection

Professional treatment options ProductActiveIngredient Application Method Application Time IMA-JetImidaclopridTrunk injectionSpring: Full canopy ImicideImidaclopridTrunk injectionSpring: Full canopy MeritImidaclopridSoil injection, drenchSpring, Fall MeritImidaclopridTrunk injectionSpring: Full canopy SafariDinotefuranSoil injection, drench; Basal bark spraySpring TranstectDinotefuranSoil injection, drench; Basal bark spraySpring Tree-AgeEmamectin benzoateTrunk injectionSpring – Fall: Full canopy TreeAzinAzadirachtinTrunk injectionSpring XytectImidaclopridSoil injection, drenchSpring, Fall ZylamDinotefuranSoil injection, drench; Basal bark spraySpring

Per Acre Use Limitations for Soil or Basal Trunk Treatments Professional product labels have specific per acre use limitations Homeowner products give ‘once per year’ limitation; some give maximum product use per acre or 1000 sq. ft.

Per Acre Use Limits – Soil, Bark Trmts Residence (on ½ acre lot) Residence (on ½ acre lot) Driveway 6 ash trees

Residence Driveway 20”dbh 13” dbh 14”dbh 8”dbh 4”dbh

4” 8” 13” 14” + 20” 67” 67 total treatable inches DBH

Professional products Active IngredientFormulation Max/ Acre/ Year Annual/ Acre Use LimitTreatment Area Max Product/ Area/ Year Total Treatable DBH – Minimum Rate Total Treatable DBH Maximum Rate >15” DBH Total Treatable Max Rate Imidacloprid2F1.6 pts0.4 lbs/a.i. 1/8 acre3.2 oz3216 EXCEEDS ½ acre12.8 oz acre25.6 oz Imidacloprid75WSP/ 75WP 0.53 lbs 0.4 lbs/ a.i. 1/8 acre1.1 oz3216 EXCEEDS ½ acre4.2 oz acre8.5 oz Dinotefuran20 SG2.7 lbs0.54 lbs/a.i. 1/8 acre5.4 oz5113 N/A ½ acre21.6 oz20652 N/A 1 acre43.2 oz N/A

Residence Treat Must use another type of treatment Must use another type of treatment “64 total inches DBH to treat” 20”dbh 13” dbh 14”dbh 8”dbh 4”dbh

Canopy sprays not recommended Limited effectiveness Need special equipment Spray drift likely Possible adverse effects to nontargets

Commercial application techniques Soil injection

Commercial application techniques Mauget trunk injection Kioritz soil injection

Commercial application techniques Arborjet systemWedgle method

Commercial application techniques iQ Tree infuser Basal bark spray

Reference PM 2084 is available as PDF at the ISU Extension Online Store