Insecticide Options for EAB Purdue

8/3/2019 Insecticide Options for EAB Purdue

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IetiieOptio oPotetiA Teeo EeaA Boe

Daniel A. HermsDeborah G. McCullougDavid R. SmitleyCliord S. SadoR. Chris WilliamsonPhilip L. Nixon


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Daniel A. Herms1, Deborah G. McCullough2,David R. Smitley3, Cliord S. Sado4, R. Chris Williamson5,and Philip L. Nixon6

1Proessor, Department o Entomology, Ohio Agricultural Research andDevelopment Center, The Ohio State University, Wooster, OH 44691

2Proessor, Department o Entomology and Department oForestry, Michigan State University, East Lansing, MI 48824

3Proessor, Department o Entomology, MichiganState University, East Lansing, MI 48824

4Proessor, Department o Entomology, PurdueUniversity, West Laayette, IN 47907

5Associate Proessor, University o Wisconsin-Madison and Universityo Wisconsin Cooperative Extension, Madison, WI 53706

6Extension Entomologist, Department o NaturalResources and Environmental Sciences, University oIllinois at Urbana-Champaign, Urbana, IL 61801

Ietiie Optio oPoteti A Tee oEea A Boe


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InsEcTIcIdE OPTIOns O POTEcTIng Ash TEEs Om EmErld Ash BOE2

cotet

Answers to Frequently Asked Questions 3

What options do I have or treating my ash trees? 3I know my tree is already inested with EABWill insecticides still be eective? 3

My ash tree looks ne but my county is quarantinedor EAB Should I start treating my tree? 4

I realize that I will have to protect my ash trees romEAB or several years Is it worth it? 4

Insecticide Options or Controlling EAB 5

Using Insecticides to Control EAB 6

Soil-Applied Systemic Insecticides 6Trunk-Injected Systemic Insecticides 7

Noninvasive, Systemic Basal Trunk Sprays 7

Protective Cover Sprays 7

How Eective Are Insecticides or Control o EAB? 8

Soil-Applied Systemic Insecticides 8

Trunk-Injected Systemic Insecticides 9

Emamectin benzoate 9

Imidacloprid 9

Noninvasive Basal Trunk Sprays with Dinoteuran 10

Protective Cover Sprays 10

Acknowledgements 10

Key Points and Summary Recommendations 11


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Herms, McCullough, Smitley, Sado, Williamson, Nixon 3

Emerald ash borer (Agrilus planipennis

Fairmaire), an invasive insect native toAsia, has killed tens o millions o ash

trees in urban, rural and orested settingsThis beetle was rst discovered in 2002 insoutheast Michigan and Windsor, Ontario Aso June 2009, emerald ash borer (EAB) ines-tations were known to be present in 12 statesand two Canadian provinces Many hom-eowners, arborists and tree care proession-als want to protect valuable ash trees romEAB Scientists have learned much about thisinsect and methods to protect ash trees since2002 This bulletin is designed to answer

requently asked questions and providethe most current inormation on insecticideoptions or controlling EAB

Awe to equetyAke Quetio

What options do I have or treating myash trees?

I you elect to treat your ash trees, there are

several insecticide options available andresearch has shown that treatments can beeective Keep in mind, however, that con-trolling insects that eed under the bark withinsecticides has always been dicult This isespecially true with EAB because our nativeNorth American ash trees have little naturalresistance to this pest In university trials,some insecticide treatments were eective in

Ietiie Optio oPoteti A Tee o

Eea A Boe

some sites, but the same treat-

ments ailed in other sites Further-more, in some studies conductedover multiple years, EAB densitiescontinued to increase in individualtrees despite annual treatmentSome arborists have combinedtreatments to increase the odds osuccess (eg, combining a coverspray with a systemic treatment)

Our understanding o how EABcan be managed successullywith insecticides has increased

substantially in recent years Thecurrent state o this understandingis detailed in the bulletin It is important tonote that research on management o EABremains a work in progress Scientists romuniversities, government agencies and com-panies continue to conduct intensive studiesto understand how and when insecticidetreatments will be most eective

I know my tree is already inested withEAB. Will insecticides still be eective?

I a tree has lost more than 50 percent o itscanopy, it is probably too late to save thetree Studies have shown that it is best tobegin using insecticides while ash trees arestill relatively healthy This is because mosto the insecticides used or EAB control actsystemically the insecticide must be trans-ported within the tree In other words, a treemust be healthy enough to carry a systemic


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insecticide up the trunk and into the branchesand canopy When EAB larvae eed, their gal-leries injure the phloem and xylem that makeup the plants circulatory system This inter-eres with the ability o the tree to transportnutrients and water, as well as insecticides Asa tree becomes more and more inested, theinjury becomes more severe Large branches

or even the trunk can be girdled by the larvalgalleries

Studies have also shown that i the canopy oa tree is already declining when insecticidetreatments are initiated, the condition o thetree may continue to deteriorate during therst year o treatment In many cases, the treecanopy will begin to improve in the secondyear o treatment This lag in the reversal ocanopy decline probably refects the timeneeded or the tree to repair its vascularsystem ater the EAB inestation has beenreduced

My ash tree looks fne but my countyis quarantined or EAB. Should I starttreating my tree?

Scientists have learned that ash trees with lowdensities o EAB oten have ew or no exter-nal symptoms o inestation Thereore, iyour property is within a county that has beenquarantined or EAB, your ash trees are prob-ably at risk Similarly, i your trees are outsidea quarantined county but are still within10-15 miles o a known EAB inestation, theymay be at risk I your ash trees are more than15 miles beyond this range, it is probablytoo early to begin insecticide treatmentsTreatment programs that begin too earlyare a waste o money Remember, however,that new EAB inestations have been discov-ered every year since 2002 and existing EABpopulations will build and spread over timeStay up to date with current EAB quaran-tine maps and related inormation at www.emeraldashborer.info You can use the linksin this Web site to access specic inormation

or individual states When an EAB inesta-tion is detected in a state or county or therst time, it will be added to these mapsNote, however, that once an area has beenquarantined, EAB surveys generally stop, andurther spread o EAB in that area will not berefected on uture maps

I realize that I will have to protect myash trees rom EAB or several years. Isit worth it?

The economics o treating ash trees withinsecticides or EAB protection are com-plicated Factors that can be consideredinclude the cost o the insecticide andexpense o application, the size o the trees,the likelihood o success, and potentialcosts o removing and replacing the treesUntil recently, insecticide products had tobe applied every year A new product thatis eective or two years or even longer(emamectin benzoate) has altered the eco-nomics o treating ash trees As research pro-gresses, costs and methods o treating treeswill continue to change and it will be impor-tant to stay up to date on treatment options

Benets o treating trees can be more dicultto quantiy than costs Landscape trees typi-

cally increase property values, provide shadeand cooling, and contribute to the quality olie in a neighborhood Many people are sen-timental about their trees These intangiblequalities are important and should be part oany decision to invest in an EAB managementprogram

It is also worth noting that the size o EABpopulations in a specic area will changeover time Populations initially build veryslowly, but later increase rapidly as moretrees become inested As EAB populations

reach their peak, many trees will decline anddie within one or two years As untreated ashtrees in the area succumb, however, the localEAB population will decrease substantiallyScientists do not yet have enough experi-ence with EAB to know what will happenover time to trees that survive the initialwave o EAB Ash seedlings and saplings arecommon in orests, woodlots, and right-o-ways, however, and it is unlikely that EAB willever completely disappear rom an area Thatmeans that ash trees may always be at somerisk o being attacked by EAB, but it seems

reasonable to expect that treatment costscould eventually decrease as pest pressuredeclines ater the EAB wave has passed


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Table 1. Insecticide options or proessionals and homeowners or controlling EAB thathave been tested in multiple university trials Some products may not be labeled or use inall states Some o the listed products ailed to protect ash trees when they were applied atlabeled rates Inclusion o a product in this table does not imply that it is endorsed by theauthors or has been consistently eective or EAB control See text or details regardingeectiveness

Insecticide Formulation Active Ingredient Application Method Recommended Timing

Professional Use Products

Merit (75WP, 75WSP, 2F) Imidacloprid Soil injection or drench Mid-all and/or mid- to late spring

XytectTM (2F, 75WSP) Imidacloprid Soil injection or drench Mid-all and/or mid- to late spring

IMA-jet Imidacloprid Trunk injection Early May to mid-June

Imicide Imidacloprid Trunk injection Early May to mid-June

TREE-geTM Emamectin benzoate Trunk injection Early May to mid-June

Inject-A-Cide B Bidrin Trunk injection Early May to mid-June

SaariTM (20 SG) Dinoteuran Systemic bark spray Early May to mid-June

Astro Permethrin

Preventive bark andoliage cover sprays

2 applications at 4-week intervals;rst spray should occur whenblack locust is blooming (earlyMay in southern Ohio to earlyJune in mid-Michigan)

OnyxTM Bienthrin

Tempo Cyfuthrin

Sevin SL Carbaryl

Homeowner Formulation

Bayer AdvancedTM Tree & ShrubInsect Control

Imidacloprid Soil drench Mid-all or mid- to late spring

Ietiie Optio ocotoi EABInsecticides that can eectively control EABall into our categories: (1) systemic insec-ticides that are applied as soil injections ordrenches; (2) systemic insecticides appliedas trunk injections; (3) systemic insecticides

applied as lower trunk sprays; and (4) pro-tective cover sprays that are applied to thetrunk, main branches, and (depending on thelabel) oliage

Insecticide ormulations and applicationmethods that have been evaluated or controlo EAB are listed in Table 1 Some are mar-keted or use by homeowners while othersare intended or use only by proessionalapplicators The active ingredient reers tothe compound in the product that is actuallytoxic to the insect

Formulations included in Table 1 have beenevaluated in multiple eld trials conductedby the authors Inclusion o a product in Table1 does not imply that it is endorsed by the


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authors or has been consistently eective orEAB control Please see the ollowing sec-tions or specic inormation about resultsrom these trials Results o some tests havealso been posted on www.emeraldashborer.info

Strategies or the most eective use o theseinsecticide products are described below It

is important to note that pesticide labels andregistrations change constantly and vary romstate to state It is the legal responsibility othe pesticide applicator to read, understandand ollow all current label directions or thespecic pesticide product being used

Ui Ietiie tocoto EAB

Soil-Applied Systemic Insecticides

Systemic insecticides applied to the soilare taken up by the roots and translocatedthroughout the tree The most widely testedsoil-applied systemic insecticide or control oEAB is imidacloprid, which is available underseveral brand names or use by proessionalapplicators and homeowners (see Table 1)All imidacloprid ormulations can be appliedas a drench by mixing the product with water,then pouring the solution directly on the soilaround the base o the trunk Dinoteuranwas recently labeled or use against EAB as a

soil treatment (in addition to its use as a basaltrunk spray discussed below) Studies to testits eectiveness as a soil treatment are cur-rently underway in Michigan and Ohio

Imidacloprid soil applications should bemade when the soil is moist but not satu-rated Application to water-logged soilcan result in poor uptake i the insecticidebecomes excessively diluted and can alsoresult in puddles o insecticide that couldwash away, potentially contaminating suracewaters and storm sewers Insecticide uptake

will also be limited when soil is excessivelydry Irrigating the soil surrounding the baseo the tree beore the insecticide applicationcan improve uptake

The application rates or the homeownerproduct (Bayer AdvancedTM Tree & ShrubInsect Control) and proessional ormulations

o imidacloprid are very similar Homeownersapply the same amount o active ingredientthat proessionals apply However, there arecertain restrictions on the use o homeownerormulations that do not apply to proessionaormulations Homeowner ormulations oimidacloprid can be applied only as a drenchIt is not legal to inject these products into the

soil, although some companies have mar-keted devices to homeowners specically orthis purpose Homeowners are also restrictedto making only one application per yearSeveral generic products containing imida-cloprid are available to homeowners, but theormulations vary and the eectiveness othese products has not yet been evaluated inuniversity tests

Soil drenches oer the advantage o requir-ing no special equipment or applica-tion other than a bucket or watering canHowever, imidacloprid can bind to suracelayers o organic matter, such as mulch or lealitter, which can reduce uptake by the treeBeore applying soil drenches, it is impor-tant to remove, rake or pull away any mulchor dead leaves so the insecticide solution ispoured directly on the mineral soil

Imidacloprid ormulations labeled or use byproessionals can be applied as a soil drenchor as soil injections Soil injections requirespecialized equipment, but oer the advan-tage o placing the insecticide under mulchor tur and directly into the root zone This

also can help to prevent runo on slopedsuraces Injections should be made just deepenough to place the insecticide beneath thesoil surace (2-4 inches) Soil injections shouldbe made within 18 inches o the trunk wherethe density o ne roots is highest As youmove away rom the tree, large radial rootsdiverge like spokes on a wheel and studieshave shown that uptake is higher when theproduct is applied at the base o the trunkThere are no studies that show that applyingertilizer with imidacloprid enhances uptakeor eectiveness o the insecticide

Optimal timing or imidacloprid soil injec-tions and drenches is mid-April to mid-May,depending on your region Allow our tosix weeks or uptake and distribution o theinsecticide within the tree In southern Ohio,or example, you would apply the product by


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mid-April; in southern Michigan, you shouldapply the product by early to mid-MayWhen treating larger trees (eg, with trunkslarger than 12 inches in diameter), treat onthe earlier side o the recommended timingLarge trees will require more time or uptakeand transportation o the insecticide than willsmall trees Recent tests show that imidaclo-

prid soil treatments can also be successulwhen applied in the all

Trunk-Injected Systemic Insecticides

Several systemic insecticide products canbe injected directly into the trunk o thetree including ormulations o imidaclopridand emamectin benzoate (see Table 1) Anadvantage o trunk injections is that they canbe used on sites where soil treatments maynot be practical or eective, including treesgrowing on excessively wet, compacted orrestricted soil environments However, trunkinjections do wound the trunk, which maycause long-term damage, especially i treat-ments are applied annually

Products applied as trunk injections aretypically absorbed and transported withinthe tree more quickly than soil applicationsAllow three to our weeks or most trunk-injected products to move through the treeOptimal timing o trunk injections occursater trees have leaed out in spring butbeore EAB eggs have hatched, or generallybetween mid-May and mid-June Uptake o

trunk-injected insecticides will be most e-cient when trees are actively transpiring Bestresults are usually obtained by injecting treesin the morning when soil is moist but notsaturated Uptake will be slowed by hot ater-noon temperatures and dry soil conditions

Noninvasive, Systemic BasalTrunk Sprays

Dinoteuran is labeled or application as anoninvasive, systemic bark spray or EABcontrol It belongs to the same chemical class

as imidacloprid (neonicotinoids) but is muchmore soluble The ormulated insecticide issprayed on the lower ve to six eet o thetrunk using a common garden sprayer andlow pressure Research has shown that theinsecticide penetrates the bark and movessystemically throughout the rest o the tree

Dinoteuran can be mixed with suractantsthat may acilitate its movement into the tree,particularly on large trees with thick barkHowever, in eld trials, adding a suractantdid not consistently increase the amounto insecticide recovered rom the leaves otreated trees

The basal trunk spray oers the advantage obeing quick and easy to apply and requiresno special equipment other than a gardensprayer This application technique does notwound the tree, and when applied correctly,the insecticide does not enter the soil

Protective Cover Sprays

Insecticides can be sprayed on the trunk,branches and (depending on the label)oliage to kill adult EAB beetles as they eedon ash leaves, and newly hatched larvae asthey chew through the bark Thorough cover-age is essential or best results Productsthat have been evaluated as cover sprays orcontrol o EAB include some specic ormula-tions o permethrin, bienthrin, cyfuthrin andcarbaryl (see Table 1)

Protective cover sprays are designed toprevent EAB rom entering the tree and willhave no eect on larvae eeding under thebark Cover sprays should be timed to occurwhen most adult beetles are eeding andbeginning to lay eggs Adult activity canbe dicult to monitor because there are no

Healthy ash trees that

have been protectedwith insecticidesgrowing next tountreated ash treeskilled by EAB.


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eective pheromone traps or EAB However,rst emergence o EAB adults generallyoccurs between 450-550 degree days (start-ing date o January 1, base temperature o50F), which corresponds closely with ullbloom o black locust (Robinia pseudoacacia)For best results, consider two applications,one at 500 DD50 (as black locust approaches

ull bloom) and a second spray our weekslater

how Efetive AeIetiie o coto oEAB?Extensive testing o insecticides or controlo EAB has been conducted by researchersat Michigan State University (MSU) and TheOhio State University (OSU) Results o someo the MSU trials are available at wwwemer-aldashborerino

Soil-Applied Systemic Insecticides

Ecacy o imidacloprid soil injections or con-trolling EAB has been inconsistent; in sometrials EAB control was excellent, while othersyielded poor results Dierences in applica-tion protocols and conditions o the trialshave varied considerably, making it dicultto reach rm conclusions about sources ovariation in ecacy For example, an MSUstudy ound that low-volume soil injections o

imidacloprid applied to small trees averag-ing 4 inches in DBH (diameter o the trunkat breast height) using the Kioritz applicator(a hand-held device or making low-volumeinjections) provided good control at onesite However, control was poor at anothersite where the same application protocolswere used to treat larger trees (13-inch DBH)Imidacloprid levels may have been too low inthe larger trees to provide adequate controlHigher pest pressure at the second site alsomay have contributed to poor control in the

large treesIn the same trials, high-pressure soil injectionso imidacloprid (applied in two concentricrings, with one at the base o the tree and theother halway to the drip line o the canopy)provided excellent control at one site Atanother site, however, soil injections appliedusing the same rate, timing and application

method were completely ineective, eventhough tree size and inestation pressurewere very similar It should be noted thatrecent studies have shown that imidaclopridsoil injections made at the base o the trunkresult in more eective uptake than applica-tions made on grid or circular patterns underthe canopy

Imidacloprid soil drenches have also gen-erated mixed results In some studiesconducted by MSU and OSU researchers,imidacloprid soil drenches have providedexcellent control o EAB However, in otherstudies, control has been inconsistent Expe-rience and research indicate that imidaclopridsoil drenches are most eective on smallertrees and control o EAB on trees with a DBHthat exceeds 15 inches is less consistent

This inconsistency may be due to the actthat application rates or systemic insecticides

are based on amount o product per inch otrunk diameter or circumerence As the DBHo a tree increases, the amount o vasculartissue, lea area and biomass that must beprotected by the insecticide increases expo-nentially Consequently, or a particular appli-cation rate, the amount o insecticide appliedas a unction o tree size is proportionallydecreased as trunk diameter increasesHence, the DBH-based application rates thateectively protect relatively small trees canbe too low to eectively protect large treesSome systemic insecticide products address

this issue by increasing the application rateor large trees

In an OSU study with larger trees (15- to22-inch DBH), XytectTM (imidacloprid) soildrenches provided consistent control o EABwhen applied experimentally at twice the ratethat was allowed at that time Recently, theXytectTM label was modied to allow the useo this higher rate, which we now recommendwhen treating trees larger than 15-inch DBHMerit imidacloprid ormulations, however,are not labeled or application at this high

rate Thereore, when treating trees greaterthan 15-inch DBH with Merit soil treatments,two applications are recommended, eitherin the all and again in the spring, or twicein the spring, about our weeks apart (orexample in late April and again in late May)This is not an option or Bayer AdvancedTMTree and Shrub Insect Control and other

EAB adults must eedon oliage beore theybecome reproduc-tively mature.


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homeowner ormulations o imidacloprid,which are limited by the label to one applica-tion per year Homeowners wishing to protecttrees larger than 15-inch DBH should con-sider having their trees proessionally treated

Treatment programs must comply with anylimits specied on the label regarding themaximum amount o insecticide that can be

applied per acre during a given year

Trunk-Injected Systemic Insecticides

Emamectin benzoate In several inten-sive studies conducted by MSU and OSUresearchers, a single injection o emamectinbenzoate in mid-May or early June pro-vided excellent control o EAB or at leasttwo years, even under high pest pressureFor example, in a highly-replicated studyconducted on trees ranging in size rom 5-to 20-inch DBH at three sites in Michigan,

untreated trees had an average o 68 to 132EAB larvae per m2 o bark surace, whichrepresents high pest pressure In contrast,trees treated with emamectin benzoate had,on average, only 02 larvae per m2, a reduc-tion o > 99 percent When additional treeswere elled and debarked two years ater theemamectin benzoate injection, there werestill virtually no larvae in the treated trees,while adjacent, untreated trees at the samesites had hundreds o larvae

In two OSU studies conducted in Toledo

with street trees ranging in size rom 15-to 25-inch DBH, a single application oemamectin benzoate also provided excel-lent control or two years There was no signo canopy decline in treated trees and veryew emergence holes, while the canopies oadjacent, untreated trees exhibited severedecline and extremely high numbers o emer-gence holes

One study suggests that a single injection oemamectin benzoate may even control EABor three years Additional studies to urther

evaluate the long-term eectiveness oemamectin benzoate are underway To date,this is the only product that controls EAB ormore than one year with a single applicationIn addition, in side-by-side comparisons withother systemic products (neonicotinoids),emamectin benzoate was more eective

Imidacloprid Trunk injections with imidaclo-prid products have provided varying degreeso EAB control in trials conducted at dierentsites in Ohio and Michigan In an MSU study,larval density in trees treated with Imicideinjections were reduced by 60 percent to 96percent, compared to untreated controlsThere was no apparent relationship between

ecacy and trunk diameter or inestationpressure In another MSU trial, imidaclopridtrunk injections made in late May were moreeective than those made in mid-July, andIMA-jet injections provided higher levels ocontrol than did Imicide, perhaps becausethe IMA-jet label calls or a greater amounto active ingredient to be applied on largetrees In an OSU study in Toledo, IMA-jetprovided excellent control o EAB on 15- to25-inch trees under high pest pressure whentrees were injected annually However, treesthat were injected every other year were not

consistently protectedIn a discouraging study conducted in Michi-gan, ash trees continued to decline rom oneyear to the next despite being injected inboth years with either Bidrin (Inject-A-CideB) or imidacloprid The imidacloprid treat-ments consisted o two consecutive years oImicide (10% imidacloprid) applied usingMauget micro-injection capsules, or anexperimental 12% ormulation o imidaclo-prid in the rst year ollowed by PointerTM(5% imidacloprid) in the second year with

both applied using the WedgleTM

Direct-InjectTM System All three treatment regimessuppressed EAB inestation levels in bothyears, with Imicide generally providingbest control under high pest pressure inboth small (six-inch DBH) and larger (16-inchDBH) caliper trees However, larval densityincreased in treated and untreated trees romone year to the next Furthermore, canopydieback increased by at least 67 percent in alltreated trees (although this was substantiallyless than the amount o dieback observedin untreated trees) Even consecutive years

o these treatments only slowed ash declineunder severe pest pressure In another MSUstudy, ACECAP trunk implants (active ingre-dient is acephate) did not adequately protectlarge trees (greater than 15-inch DBH) underhigh pest pressure

EAB larvae damagethe vascular system o

the tree as they eed,which intereres withmovement o systemicinsecticides in thetree.


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Noninvasive Basal Trunk Sprays withDinoteuran

Studies to date indicate that systemic basaltrunk sprays with dinoteuran are about aseective as imidacloprid treatments MSUand OSU studies have evaluated residuesin leaves rom trees treated with the basaltrunk spray Results show that the dinoteuraneectively moved into the trees and wastranslocated to the canopy at rates similar tothose o other trunk-injected insecticides, andaster than other soil-applied neonicotinoid

productsAs with imidacloprid treatments, control oEAB with dinoteuran has been variable inresearch trials In an MSU study conductedin 2007 and 2008, dinoteuran trunk spraysreduced EAB larval density by approxi-mately 30 percent to 60 percent comparedto the heavily inested untreated trees Thetreatment was eective or only one yearand would have to be applied annually Ingeneral, control is better and more consistentin smaller trees than in large trees, but more

research is needed with larger trees Studiesto address the long-term eectiveness oannual dinoteuran applications or control oEAB are underway

Protective Cover Sprays

MSU studies have shown that applicationso OnyxTM, Tempo and Sevin SL providedgood control o EAB, especially when theinsecticides were applied in late May andagain in early July Acephate sprays were lesseective BotaniGard (Beauvaria bassiana)was also ineective under high pest pres-

sure Astro (permethrin) was not evaluatedagainst EAB in these tests, but has beeneective or controlling other species owood borers and bark beetles

In another MSU study, spraying Tempojust on the oliage and upper branches orspraying the entire tree were more eectivethan simply spraying just the trunk and largebranches This suggests that some coversprays may be especially eective or con-trolling EAB adults as they eed on leavesin the canopy A single, well-timed spray

was also ound to provide good control oEAB, although two sprays may provide extraassurance given the long period o adult EABactivity

It should be noted that spraying large treesis likely to result in a considerable amount oinsecticide drit, even when conditions areideal Drit and potential eects o insecti-cides on non-target organisms should beconsidered when selecting options or EABcontrol

AkoweeetProduction and distribution o this bulletinwere supported in part by cooperative agree-ments rom the US Department o Agricul-tures Animal and Plant Health InspectionService (USDA-APHIS) and the US ForestService, Northeastern Area, Forest HealthProtection This bulletin may not necessarilyexpress the views o the USDA


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Key Poit a suayeoeatio

Insecticides can eectively protect ash trees rom EAB

Unnecessary insecticide applications waste money I EAB hasnot been detected within 10-15 miles, your trees are at low

risk Be aware o the status o EAB in your location Currentmaps o known EAB populations can be ound at www.emer-aldashborer.info Remember, however, that once a county isquarantined, maps or that county are no longer updated

Trees that are already inested and showing signs o canopydecline when treatments are initiated may continue to declinein the rst year ater treatment, and then begin to showimprovement in the second year due to time lag associatedwith vascular healing Trees exhibiting more than 50 percentcanopy decline are unlikely to recover even i treated

Emamectin benzoate is the only product tested to date thatcontrols EAB or more than one year with a single application

It also provided a higher level o control than other productsin side-by-side studies

Soil drenches and injections are most eective when made atthe base o the trunk Imidacloprid applications made in thespring or the all have been shown to be equally eective

Soil injections should be no more than 2-4 inches deep, toavoid placing the insecticide beneath eeder roots

To acilitate uptake, systemic trunk and soil insecticidesshould be applied when the soil is moist but not saturated orexcessively dry

Research and experience suggest that eectiveness o insecti-

cides has been less consistent on larger trees Research hasnot been conducted on trees larger than 25-inch DBH Whentreating very large trees under high pest pressure, it may benecessary to consider combining two treatment strategies

XytectTM soil treatments are labeled or application at ahigher maximum rate than other imidacloprid ormulations,and we recommend that trees larger than 15-inch DBH betreated using the highest labeled rate Merit imidaclopridormulations are not labeled or use at this higher rate Whentreating larger trees with Merit soil treatments, best resultswill be obtained with two applications per year Imidaclopridormulations or homeowners (Bayer AdvancedTM Tree &

Shrub Insect Control and other generic ormulations) can beapplied only once per year

Homeowners wishing to protect trees larger than 15-inchDBH should consider having their trees proessionally treated

Treatment programs must comply with any label restrictionson the amount o insecticide that can be applied per acre in agiven year


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The Cooperative Emerald Ash Borer Program

For more information and to orderadditional copies of this bulletin:

www.emeraldashborer.info/

The Ohio State University EAB Outreach Team

www.ashalert.osu.edu

Purdue Extension

www.entm.purdue.edu/eab/

University of Wisconsin

www.entomology.wisc.edu/emeraldashborer/

University of Illinois

ipmillinoisedu/landtur/insects/

University of Minnesota

www.extension.umn.edu/issues/eab/


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Bibliographic Citation: Herms DA, McCullough DG, Smitley DR, Sadof C, Williamson RC, and Nixon PL. 2009.Insecticide options for protecting ash trees from emerald ash borer. North Central IPM Center Bulletin. 12 pp.

June 2009

Documents

Insecticide Options for EAB Purdue