Wood-boring Insectsof Trees and Shrubs

B-508601-08

Bastiaan M. Drees, John A. Jackman and Michael E. Merchant*

M any insects feed and make their homesin the bark, trunks and branches ofshade trees and shrubs in Texas. Insect

borers belong to several different insect groupsincluding a variety of beetles, moths and horntailwasps.

Most insect borers are attracted to weakened,damaged, dying or dead plants. These are referred toas “secondary invaders” because they attack onlyafter a plant has been weakened by another stress.Secondary invaders are a symptom of other prob-lems with the health of the tree or shrub, but maycontribute to its decline. Secondary invaders includespecies from groups already mentioned, but alsomay include termites, carpenter bees and carpenterants.

Many other insects live in dying or dead trees,including natural enemies (predators and parasites)of the insect borers, sap or fungi feeders, or specieswhich merely use the spaces provided by the tunnelsand galleries as living quarters.

Wood-boring insects that attack healthy treesand shrubs are called “primary invaders.” Primaryinvaders may eventually kill trees.

DamageBorer infestations often go unnoticed until plants

or parts of plants begin to die or show external signsof damage. Wood-boring insects often produce saw-dust-like frass (excrement). Their holes are normallyround, oval or semicircular and are found in a ran-dom pattern on the plant. Woodpecker damage issometimes confused with that of wood-boring bee-tles; however, woodpecker damage will not producefrass. One woodpecker, the yellow-bellied sapsucker,

*Professor and Extension Entomologist; Professor and ExtensionEntomologist; and Professor and Extension Urban Entomologist,The Texas A&M University System.

produces square holes in rows around a trunk orbranch. (See photo on page 6.)

Borers tunnel in the inner bark layer (cambium),which transports nutrients and water to the leaves.When the cambium layer is completely girdled theplant eventually dies above or beyond the damagesite. Partial girdling reduces plant growth and vigorabove the site of attack. On occasion, tunnelingmakes the tree weak, causing limbs and branches tofall. Borer damage can severely affect the quality oflumber and can make trees susceptible to disease.

Wood-boring InsectsLong-horned beetles or round-headedborers (Coleoptera: Cerambycidae)

Adults are called long-horned beetles (Fig. 1)because their antennae are occasionally longer thantheir bodies. Larvae tunnel underneath bark andinto the heartwood. The tunnels are oval to almostround in cross section because of the round shape ofthe larvae (Fig. 2). Larvae of some species are leg-less, but most have three pairs of small legs on thefirst three segments behind the head capsule. Whiletunneling, larvae continually pack their tunnels withexcrement (frass), which looks like compressedwood fibers, or push frass out of the holes they pro-duce. This excrement, along with the sap exuded bythe plant in response to the damage, is often visibleon the outside of infested trunks or branches. Manyspecies of beetles belong to this group, but most aresecondary invaders. Some examples of long-hornedbeetles are described below.

Locust borer (Megacyllene robiniae) adults aremedium-sized (3⁄4 inch long) long-horned beetlesfrequently found feeding on goldenrod or otherflowers in the fall. They are dark brown to blackwith distinctive gold-yellow markings. Larvaehatch from eggs laid in bark crevices. Visiblesymptoms of infestation are wet spots

and frass on the bark of black locusts. Later, lar-vae tunnel into the inner bark and construct cellsin which they spend the winter months. In a yearthe larvae are fully grown and about an inch inlength.Cottonwood borer (Plectrodera scalator) is fre-quently found on cottonwood, poplar or willowtrees. Adult beetles are large (11⁄4 inches long) withan attractive black and whitish-yellow pattern.They are active from May through August. Thelarvae (1.75 to 2 inches long) tunnel at the base ofthe trunk or below ground level. They requireabout 2 years to develop.Red-headed ash borer (Neoclytus acuminatus) isone of the most common wood-boring beetles. Ithas a narrow body with a reddish thorax andlight brown wing covers marked with four yellowlines on each. The yellow lines are slanted down-ward toward the middle, giving the appearanceof a “V” across the back. The antennae are rathershort and the long legs are thin and fragile. Red-headed ash borers feed in many species of woodincluding ash, oak, elm and even grapes. Adultscan be found on dead log piles and frequentlyemerge from firewood.Red oak borer (Enaphalodes rufulus) attacks oak

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Figure 1. Long-horned beetles or roundheaded borers: locust borer(left); cottonwood borer (center); and red-headed ash borer (right).

Red oak borer larvae girdle main trunks andbranches during the second year of larvaldevelopment.

Female twig girdler beetles chew a V-shapedgroove entirely around twigs, branches or ter-minals. (Photo by M. E. Rice)

Twig and branch pruner larvae girdle fromunderneath the bark.

and maple trees and can be a serious pest in nurs-eries. The reddish-brown adults (5⁄8 to 11⁄8 incheslong) lay eggs individually in bark crevices dur-ing July and August. Larvae tunnel under thebark and into the heartwood. Infested sites can berecognized by the frass around the buckled barknear the gallery entrance. Larvae often tunnelcompletely around the trunk or branches theyinfest, producing noticeable scars or girdling. Redoak borers feed for more than a year beforepupating in chambers tunnelled into the heart-wood. Damage kills limbs or terminals andincreases the risk from secondary invaders anddiseases.Twig girdler (Oncideres species) damage occursprimarily from egg laying. This insect attackspecan, mimosa, chinaberry and huisache. Thegrayish-brown adults (11⁄16 inch long) girdle limbsduring the fall (late August through mid-November) by chewing a V-shaped groove entire-ly around twigs, branches or terminals. Eggs areinserted into the bark on the girdled part of thebranch away from the tree. Girdled limbs eventu-ally break and fall to the ground, particularly dur-ing high winds and storms. Damage can disfigurea young tree and leads to secondary branching,particularly if the terminal is attacked. Larvaereach up to 7⁄8 inch long and are unable to developin healthy sapwood. Removing the girdled twigsand branches from the ground during winter andspring and destroying them can reduce the popu-lation of these insects.Twig and branch pruners (Elaphidionoides andAgrilus species) produce damage superficiallysimilar to that of twig girdlers on elm, hackberry,hickory, maple, oak, pecan, persimmon, redbud,sweetgum and other trees. In these species, how-ever, it is the larvae that girdle twigs and branch-es underneath the bark. The surface of the sev-ered end of the twig is smooth. The insect usuallysevers branches where small twigs branch fromthe main, girdled branch.

Metallic wood-boring beetles(or flat-headed borers)(Coleoptera: Buprestidae)

Adult beetles are flattened, hard-bodied and boat-shaped with short antennae. These are beautiful bee-tles with distinctive metallic colors (green, blue,bronze, copper). Larvae are cream-colored and leg-less with widened, flattened body segments justbehind the heads. Consequently, when these larvaetunnel beneath bark or into the sapwood they pro-duce oval or flattened tunnels in cross section (Fig.2). Galleries are often winding and packed withfrass. Tunneling can girdle trunks and branches.Many species of flat-headed borers occur in thestate. Most are secondary invaders.

Examples of flat-headed borers include thebronze birch borer (Agrilus anxius), uncommon inTexas because of the lack of host trees; Agrilusspecies found on oak and raspberry (A. bilineatusand A. ruficollis, respectively); flat-headed appletreeborer (Chrysobothris femorata) and a closely relatedspecies that attacks recently transplanted or stressedshade, pecan and fruit trees.

Bark beetles(Coleoptera: Curculionidae)

Beetles in this group tunnel below the bark oftrees and/or into the wood. Adult beetles are smalland reddish-brown to black. Larvae are cream-colored grubs without legs. One member of thisgroup, the European elm bark beetle (Scolytus multis-triatus), is the carrier of Dutch elm disease. It occursin the Texas Panhandle, but is infrequently encoun-tered in other parts of Texas. Other members of thisgroup are described below.

Southern pine beetle (Dendroctonus frontalis) is aprimary pest of southern pine forests. Adult bee-tles are active during warmer months (when tem-peratures are above 58 degrees F), and dispersewidely to injured, weakened or stressed trees inthe spring. Seven or more generations may be

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Figure 2. Larvae of round-headed borer (left) and flat-headed borer(right) with cross sections of tunnels (above).

Figure 3. Metallic wood-boring beetles or flat-headed borer adults:Agrillus bilineatus (left); flat-headed appletree borer (right).

Figure 4. Bark or engraver beetles: Southern pine beetle (left); Ipsengraver beetle (center) and granulate ambrosia beetle (right).

"Pitch tubes" are commonly seen on the trunks of pines attacked bypine bark beetles.

completed within a year. When abundant, theycan attack healthy trees. Larvae tunnel beneaththe bark producing tunnels or galleries in patternsresembling the letter “S” (Fig. 5). This tunnellingquickly disrupts the cambium layer, girdling thetree. Infested trees can have numerous masses ofresin called "pitch tubes" on the tree trunk.Needles of newly attacked trees turn reddish-brown 1 to 2 months after infestation during thesummer, and up to 3 months afterward in the

winter. Removal and destruction of infested treesmay prevent healthy trees in the vicinity frombeing attacked.Ips engravers (Ips. spp.) are often mistaken forthe southern pine bark beetle because theirappearance and damage are similar. Their gallerypatterns tend to be more parallel to each other,however (Fig. 5). Ips usually attack weakenedtrees only. Recently felled wood should be cov-ered with plastic to prevent Ips beetle infestation.The black turpentine beetle, Dendroctonus tene-brans, is another species attacking pines.Shothole borers (Scolytus rugulosus) are sec-ondary pests of common fruit trees (peach andplum), wild plums and occasionally ash, elms andhawthorne. These bark beetles tunnel through thebark and make small holes in the bark crevices.Granulate ambrosia beetle (Xylosandrus crassius-culus) is a newly introduced species that attackshealthy, stressed or freshly cut elm, pecan, peach,Prunus species, oak, sweetgum and other trees ineast Texas. Tiny (2 to 3 millimeters long), darkreddish-brown adult female beetles tunnel intotwigs, branches or small tree trunks, excavating asystem of tunnels in the wood or pith in whichthey lay eggs. They also introduce a fungus onwhich the larvae feed. Visible damage includeswilted leaves on infested branches and protru-sions of compressed wood dust from numeroussmall holes, resembling toothpicks pointing out-ward. Dead and dying areas of bark (cankers) canform at the damage site, eventually girdling thetree and killing it. There are several generationsper year. Chemical control of this species has beengenerally unsuccessful. Native ambrosia beetlesare also called shot-hole or pine-hole borers.These species have similar biologies but rarelyattack healthy, vigorous trees.

Weevils(Coleoptera: Curculionidae)

Adult weevils have a characteristic snout thatbears the chewing mouthparts (Fig. 6). Larvae arelegless and cream-colored, and generally feed incells or hollowed out cavities underneath the barkrather than in galleries or tunnels as do bark beetles.Virginia pine plantings in Texas have suffered exten-sive damage from the deodar weevil, Pissodesnemorensis. These weevils attack the trunks duringthe winter, where young trees are in poor plantingsites. Several weevil species attack the bases androots of woody ornamental plants.

Wood-boring caterpillars(Lepidoptera)

These insects are the immature stages of severalkinds of moths. Caterpillars can be easily identifiedby their “false legs” (prolegs) with tiny rows of

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Figure 5. Left to right: "S"-shaped egg galleries of the Southern pinebeetle; "Y"- or "H"-shaped egg galleries of the Ips engraver beetles.

Protrusions of compressed wood dust signal attack by the granulateambrosia beetle.

Figure 6. Deodar weevil larva, pupa and adult.

hooks on the undersides of some of the abdominalsegments (Fig. 7). Adult moths are rarely seenexcept when reared from the host plants or collectedin blacklight traps. Several kinds of moth larvae tun-nel into woody ornamental plants:

Carpenterworms (Prionoxystus robinae) are largelarvae that tunnel through the trunks of oak, elm,black locust, willow, ash, boxelder, poplar, cotton-wood, Chinese tallow and fruit trees such as pearand cherry. These larvae develop over 2 or 3years, initially feeding underneath the bark butlater tunnelling into the heartwood. Outwardsigns of attack include piles of sawdust and excre-ment, particularly in cracks and crevices.Carpenterworms may enter and exit the trunk ofthe tree several times during their development.Several closely related species with similar lifecycles also occur in Texas, but may develop inother host trees. Adult moths, which emerge inthe spring, are rather large with spotted wings.Peach tree borer (Synanthedon exitiosa) is one ofthe most important insect pests of peach andplum. Adult peach tree borer moths mate and laytheir eggs on the trunks of peach and plum(Prunus species) trees during August andSeptember. These daytime fliers are one of severalspecies often called clear-wing moths, and theylook superficially like wasps (Fig. 7). Larvae hatchfrom eggs in about 10 days and tunnel beneaththe bark for 10 to 11 months before emergingfrom the base of the trunk. Infected trees exhibitdieback, yellowing of leaves, stunted growth andpossible death if larvae girdle the trunk near thesoil line (from 10 inches above the ground to 3inches below the ground). After emerging, theydrop to the soil to pupate at the base of the tree.Affected trees can be identified by masses of saparound damage sites at the base of the trunk.Infestations can kill scaffolding limbs or entiretrees.Other species of clearwing moths are: 1) the lilacor ash borer (Podosesia syringae), which has itsadult flight period during the spring and earlysummer; 2) the dogwood borer (Synanthedon scit-ula); and 3) the lesser peach tree borer(Synanthedon pictipes).Other caterpillar pests that occur in Texas include:the southern pine coneworm (Dioryctria amatella),which tunnels around the bases of Virginia pinetrunks (Fig. 8); Euzophera ostricolorella, a root col-lar borer that infests potted magnolia; and theAmerican plum borer (Euzophera semifuneralis),which invades damaged or improperly prunedbranches on a wide variety of woody ornamen-tals.

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Figure 8. Southern pine coneworm larva (top), pupa (middle) and adult(bottom).

Figure 7. Clear-wing moth and underside of larva showing true legs(right) and false legs (prolegs) bearing tiny rows of hooks (crochets).

ManagingWood-boring InsectsPrevention

Since most wood-boring insects are consideredsecondary invaders, the first line of defense againstinfestation is to keep plants healthy. Proper care oftrees and shrubs discourages many borer pests andhelps infested plants survive. Good sap flow fromhealthy, vigorously growing trees, for example,defends the plant from damage by many borerpests. Good horticultural practices include:

� Selecting well adapted species of trees andshrubs that are not commonly attacked bywood borers in your area. Arizona ash, birch,cottonwood, locust, soft maple, flowering stonefruits (such as peaches and plums), slash pines(in west Texas), willow and poplar are especial-ly prone to borer attack.

� Choosing and preparing a good planting siteto avoid plant stress, freeze damage, sun scaldand wind burn.

� Minimizing plant stress and stimulatinggrowth by using proper watering and fertiliza-tion practices.

� Avoiding injury to tree trunks from lawn mow-ers, weed trimmers or construction.

� Promptly caring for wounded or broken plantparts using pruning or wound paint during allbut the coldest months of the year.

� Properly thinning and pruning during coldermonths.

� Removing and destroying infested, dying ordead plants or plant parts, including fallenlimbs.

� Wrapping tree trunks and limbs with quarter-inch hardware cloth spaced about 11⁄2 inchesfrom the tree’s surface where woodpeckerdamage is likely.

Wrapping trunks to prevent borer attack is inef-fective and may, under certain conditions, increasethe rate of infestation. Using plastic trunk protectorsto help prevent injury from lawn mowers and weedtrimmers is a good idea.

Non-chemical controlfor infested plants

Once trees and shrubs are infested, non-chemicaloptions for borer control are limited. One option isto remove and destroy heavily infested or injuredplants. Also, inspect damage sites closely to deter-

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Sapsucker damage appears as square holes in a tree trunk.

mine if the larvae can be extracted from the plantwith a pocket knife, wire or other suitable tool.

Chemical controlBecause stressed, unhealthy trees are more sus-

ceptible to insect attack, maintaining overall treehealth is vital in reducing the risk of wood-boringinsect infestations and limiting the need for costlyand environmentally damaging insecticides. Oldertrees and those damaged by drought or other envi-ronmental stress also will not benefit from controlefforts.

Table 1 lists some insecticides registered by theEnvironmental Protection Agency (EPA) for wood-boring insect control on trees and shrubs. Some ofthese products are for professional or commercialuse only and not available at retail outlets. In addi-tion, the product labels specify where the product isto be used, such as nurseries or landscapes, andwhich pest or pest category it targets. Choose prod-ucts according to the labeled restrictions. Do not useinsecticides on fruit or nut trees unless specificallylabeled for them. Some products sold mainlythrough specialty stores may require the purchaserto have a Texas Department of Agriculture pesticideapplicator’s license.

Application timing and method also may be spec-ified on the label. Some products are preventiveonly; others are to be used during the target pest’sadult flight periods. Bark sprays target egg-layingfemales or the adult stages emerging from the hostplant. They also may kill small larvae. Bark sprays

Figure 9. Sites where borers are most likely to enter a tree. The shadedareas are the most critical sites for treatment to prevent borer entry.

Otherwise they should be disposed of using direc-tions provided by city, county or state pesticideauthorities.

Only a few products for controlling wood-boringinsects are available at retail stores. Occasionallythese products’ containers have labels that are tapedto the container and cannot be read before purchase.The products’ names may indicate target pests, suchas Fertilome® Borer, Bagworm, Tent Caterpillar &Leafminer Spray, but the actual label has use direc-tions for only the peach twig borer (a caterpillar of aclearwing moth species) on fruit trees. In othercases, lists of pests on products that are availableonly to commercial applicators are more extensivethan those on products available to homeowners,such as those containing the pyrethroid insecticides,bifenthrin and permethrin.

generally use residual insecticides such as carbarylor pyrethroid insecticides such as bifenthrin or per-methrin. Only a few products are effective on larvaetunneling beneath the bark, such as that of the flat-headed borer beetles. These systemic products usu-ally are applied as soil drenches so the insecticidecan be absorbed by the roots or injected into thetrunk; the insecticide imidacloprid is applied aseither a soil drench or a trunk injection. Dinotefuranalso may provide some control of wood-boring bee-tles.

Retail sale of diazinon, chlorpyrifos (Dursban®)and endosulfan (Thiodan®) products have been dis-continued. Diazinon and lindane are no longeravailable for insect control and chlorpyrifos is avail-able only for use in commercial nurseries. Productscontaining these ingredients may still be usedaccording to label directions if you first contact themanufacturer to ascertain that usage is allowed.

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Insecticideclass

Activeingredient Trade name

Trunk sprays

carbamate carbarylSevin® Brand 4F Carbaryl InsecticideGardenTech® Sevin® Ready To Use Bug Killer

organophosphate chlorpyrifos Dursban® 50W

pyrethroid bifenthrin

OnyxPro™ InsecticideTalstar® P Professional InsecticideOrtho® Bug-B-Gone®

MAX® Lawn & Garden Insect Killer Concentrate

pyrethroid permethrinAstro® InsecticideBonide® Borer-Miner Killer ConcentrateBonide® Total Pest Control Concentrate Outdoor Formula

spinosyns spinosad Ferti.lome® Borer, Bagworm, Tent Caterpillar & Leafminer Spray

Soil drenches

neonicotinoid imidaclopridMarathon® 60 WPBayer Advanced™ 12 Month Tree & Shrub Insect ControlDiscus™ Nursery Insecticide

neonicotinoid dinotefuran Spectracide Tree & Shrub + Fertilizer Concentrate

Tree injection products

organophosphate acephateAcecap® 97 Systemic Insecticide Tree ImplantsAcejet Systemic insecticide for Micro-Infusion™

organophosphate dicrotophos Inject-A-Cide B®

organophosphate oxydemetonmethyl Mauget Inject-A-Cide®

neonicotinoid imidaclopridIMAjet Systemic InsecticideMauget® Imicide Systemic Injecticide for tree injection use in ready to use capsules

Table 1. Examples of current insecticides and products registered for “insect borers of trees and shrubs.” See product labels or Appendix 1 for morespecific listings of use sites, user descriptions and insect species or groups.

Know pesticide regulations. Insecticide use isregulated by the Environmental Protection Agency’sFederal Insecticide, Fungicide, and Rodenticide Act(FIFRA:http://www.epa.gov/pesticides/regulating/fifra.pdf) and Texas Department of Agriculture.

� The law mandates that pesticides be usedaccording to label directions with a few exemp-tions: An user can use an insecticide for pestsnot listed on the product label as long as theuse site is listed. Section 2(ee) of FIFRA (page13) allows for the use of any registered pesti-cide “against any target pest not specified onthe labeling if the application is to the crop,animal, or site specified on the labeling...”Thus, if a particular insect borer is not listed ona product labeled for use on trees and shrubsbut others are listed, or other products includemention of those pests, that product may beused to try to control the unlisted pest.

� Some products claiming insect control nowbeing sold may not be registered by the EPAbecause of an exemption described in Section25 (b) (on page 89 and on the Web sitehttp://www.epa.gov/PR_Notices/pr2000-6.pdf). Only those pesticides registered by theEPA are listed in this publication.

Both of these sections are also discussed further atthe Web site: http://www.epa.gov/pesticides/regulating/labels/label_review_faq.htm#pesticide.

FirewoodAdult wood borers sometimes emerge from fire-

wood stored indoors. While most of these insects arenot considered harmful, old house borer and pow-derpost beetles will attack seasoned, dry woodinside the home (see the Texas AgriLife ExtensionService publication E-394, “Structure-InfestingWood-Boring Beetles”). Treating firewood withinsecticide is both ineffective and potentially dan-gerous to the homeowner. Wood should be storedoutdoors away from the house until just before use.If firewood is infested with borers it can be treatedby wrapping it in a tarp and allowing sunlight toheat it. Stacking wood layers in alternate directionswill help it dry and reduce areas that can harborinsects. Firewood can spread exotic wood-borerspecies. Do not transport firewood to new areas,such as out-of-state camp grounds. Obtain campfirewood locally for use on such occasions.

Policy Statementfor Making ChemicalControl Suggestions

All pesticides are potentially hazardous to peopleand the environment. Pesticide users are legallyrequired to read and carefully follow all directionsand safety precautions on the container label. Theuser is always responsible for the effects of pesticideresidues, as well as problems that could arise fromdrift or movement of the pesticide to neighboringareas. Label instructions are subject to change, soread the label carefully before buying or using anypesticide. Proper disposal of leftover pesticides and“empty” or used containers is an essential step insafe pesticide use. Never pour leftover pesticidesdown a drain.

Regardless of the information provided in anExtension publication, always follow the product’slabel. When in doubt about any instructions, contactthe pesticide seller or the manufacturer listed on thelabel. Store all pesticides in their original, labeledcontainers and keep them out of the reach of chil-dren.

Suggested pesticides must be registered andlabeled for use by the Environmental ProtectionAgency and the Texas Department of Agriculture.The status of pesticide label clearances is subject tochange and may have changed since this publicationwas printed. County Extension agents and appropri-ate specialists are advised of changes as they occur.

References(Available from the Texas AgriLife Extension

Service)L-1826, Carpenter BeesE-412, Carpenter AntsE-394, Structure-Infesting Wood-Boring BeetlesTable 1 lists generic or approved common names

for insecticides. These ingredients may be found in alarge number of products, whereas trade names areused by specific manufacturers or distributors ofthese insecticides. For convenience, examples ofsome of the most commonly available trade namesfor these generic ingredients are given on page 7.

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AppendixSummary of information obtained from product

labels for treatment of wood-boring insects of treesand shrubs currently registered by theEnvironmental Protection Agency. Read and careful-ly follow directions provided on the actual productlabel.

Trunk spraysCarbaryl, a carbamate insecticide

Sevin® Brand 4F Carbaryl Insecticide (43.0 per-cent carbaryl): Caution. For agricultural or commer-cial use only. In forested areas such as non-urbanforests, tree plantations, Christmas tree farms, parksand rural shelter belts, and for rangeland trees, fortreating cypress tip moth, locust borer, Nantucketpine tip moth, olive ash borer and pitch pine tipmoth, apply 1 quart of product per acre; as a preven-tive treatment only, for elm bark and Ips engraverbeetles apply as a trunk spray a 2 percent solution(5 fluid ounces per gallon) per acre no more thantwo times per year. On pecans for twig girdler,apply 2 to 5 quarts of product per acre. On peaches,plums, prunes and nectarines, apply 2 to 3 quarts ofproduct per acre for lesser peachtree borer or peachtwig borer. Observe bee caution. Repeat applicationsas necessary up to a total of three times per year percrop but not more often than once every 7 days. Forlesser peachtree borer, thoroughly spray the limbsand tree trunks at weekly intervals during mothflight. Also see the product labels for rates of otherformulations: Sevin® Brand 80S, 80WSP and XLRPlus Carbaryl Insecticides.

GardenTech® Sevin® Ready To Use Bug Killer(0.126 percent carbaryl): Caution. For trees includingshade trees and those in shelter belts, plantations,parks and recreational areas, and for ornamentalsincluding roses and wooded shrubs; for treatingEuropean pine shoot moth, locust borer, Nantucketpine tip moth, ash borer, pitch pine tip moth andsubtropical pine tip moth. Where pests appear,direct the spray toward the upper and lower leafsurfaces and small trunks, stems and twigs to thepoint of runoff. Repeat as necessary up to a total offour times for trees and six times for ornamentalsand shrubs but not more often than once every 7days. On fruit trees including peaches and plum, fortreating lesser peachtree borer and peach twig borer.Do not apply within 3 days of harvest.

Chlorpyrifos, an organophosphateinsecticide

Dursban® 50W (50.0 percent chlorpyrifos):Danger. For use by certified applicators or peopleunder their direct supervision; this product may beused only on ornamentals grown in nurseries and to

treat evergreens, shade and flowering trees, andnonbearing fruit trees infested with:

� Weevils such as blackvine, cranberry, yellowpoplar and pine reproduction weevils, use 1pound per 100 gallons;

� Borers, including clearwing moths such as ash,dogwood, lesser peachtree, lilac, oak,peachtree, rhododendron borers; metallic woodborers such as bronze birch, flatheaded apple-tree and twolined chestnut borers; longhornedborer beetles such as cottonwood, locust, redoak borers, pales weevil adults andZimmerman pine moth: Use 2 pounds per 100gallons, spraying trunks and lower limbs oftrees and shrubs when adults begin to emergefor borers, and for peachtree borers sprayingflowering trees and shrubs on the genus Prunusas a trunk spray before newly hatched larvaeenter trees and thoroughly wet all bark areasfrom ground level to scaffold limbs;

� Pales and northern pine weevils, use 6 poundsper 100 gallons applied as a cut stump spray ordrench;

� Other beetles such as ambrosia, Anobiidae,black turpentine, European elm bark, mountainpine, native elm bark and southern pine bee-tles: Use 16 pounds per 100 gallons, to achievea preventive treatment by spraying the maintrunk of trees in the early spring or when thethreat of attack exists from nearby infestedtrees or to achieve remedial treatments spray-ing the main trunk of infested trees or logswhen damage occurs but before beetles beginto emerge;

� Weevils such as northern pine, pitch eatingweevils: Use 32 pounds per 100 gallons forpine seedlings, treating immediately aftertransplanting to thoroughly wet the foliageand stems to the point of runoff, not usingmore than 6 gallons of spray dilution per acre.

Bifenthrin, a pyrethroid insecticideOnyxPro™ Insecticide (23.4 percent bifenthrin):

Warning. For commercial nonfood use in interi-orscapes and on outdoor ornamentals, Christmastrees, nurseries, golf courses and other listed sites.Use as trunk sprays to ornamental trees includingChristmas trees to control bark beetles and boringbeetles, not applying more than 12.8 fluid ounces(0.2 pounds of active ingredient) of this product totrees per acre using spray volumes as directed onthe product label and spraying until the bark is thor-oughly wetted. Use specifically for:

� Dendroctonus bark beetles such as mountainpine beetle, southern pine beetle, and black tur-pentine beetle and engraver (Ips Species) bee-tles at 16.32 fluid ounces per 100 gallons,applying to the trunk of the tree with a

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hydraulic sprayer in the early spring or beforeadult flight and tree infestation, applying thespray directly to the main trunk from the baseof the tree to at least halfway into the livecrown;

� Other bark beetles such as ambrosia beetles,elm bark beetles and metallic wood borers at16.32 fluid ounces per 100 gallons, sprayingmixture to the trunk, scaffolding and limbs ofthe tree with a hydraulic sprayer in the earlyspring or before beetle flight and tree infesta-tion;

� Clearwing moth borers such as ash borer,banded ash clearwing, dogwood borer, lesserpeachtree borer, lilac borer, oak borer,peachtree borer, rhododendron borer andcoleopteran borers such as bronze birch borerand flatheaded appletree borer use 6.4 to 12.8fluid ounces per 100 gallons, spraying thebranches and trunks prior to adult emergence.

Talstar® P Professional Insecticide (7.9 percentbifenthrin): Caution. For use outdoors on residen-tial, institutional, public, commercial and industrialbuildings, greenhouses, lawns, ornamentals, parks,recreational areas and other listed sites. For orna-mentals and trees including but not limited to treesand shrubs, greenhouses and interiorscapes, to con-trol:

� Beetles including twig borers and weevils, use10.8 to 21.7 fluid ounces per 100 gallons, treat-ing trunks, stems and twigs in addition toplant foliage;

� Pine shoot beetle adults use 21.7 to 43.5 fluidounces per 100 gallons.

Ortho® Bug-B-Gone® MAX® Lawn & GardenInsect Killer Concentrate (0.3 percent bifenthrin):Caution. For use on shrubs and small, nonbearingtrees for northern pine weevil, pine shoot weeviland Zimmerman pine moth, and on fruit trees forpeachtree borer and lesser peachtree borer.

Permethrin, a pyrethroid insecticideAstro® Insecticide (36.8 percent permethrin):

Caution. For use on ornamental trees and shrubsaround buildings, parks, recreational areas andother listed sites, such as ornamental greenhouse,interiorscapes and plantscapes, lawns, trees andshrubs. On ornamental trees, for:

� Clearwing moth borers such as banded ashclearwing, dogwood borer, lesser peachtreeborer, lilac borer, oak borer, peachtree borerand rhododendron borer: Use 1 to 2 quarts pergallon;

� Bark beetles such as Dendroctonus sp., Ipsspecies, elm bark beetles, mountain pine beetle,pine engravers, turpentine beetles and whitepine beetle: Use 2 to 5 quarts per gallon;

� Coleopteran borers such as bronze birch borerand flatheaded appletree borer: Use 2 to 5quarts per 100 gallons;

� Maximum residual control of all the insects list-ed above, use 5.35 quarts per 100 gallons.Apply to the lower branches and trunks priorto adult emergence, which varies according topest species, host tree, environmental condi-tions and geographical location. Thorough cov-erage of bark is required for control;

� Nantucket pine tip moth, coneworms and seed-bugs, use 4 to 8 fluid ounces per 100 gallons.Use 5 to 10 gallons of finished spray per treefor coneworms and seedbugs. Begin applica-tion when the adults appear. Repeat applica-tions may be made on 5- to 7-day intervals asneeded;

� On noncommercially grown peach trees, forlesser peachtree borer and peach twig borer use1/4 to 3/4 teaspoon per gallon for 436 square feet.Do not harvest fruit within 14 days after appli-cation. Do not apply more than 3 3/4 teaspoonper 436 square feet per year.

Bonide® Borer-Miner Killer Concentrate (2.50percent permethrin): Caution. Protects fruits, nuts,trees, shrubs, roses, flowers and vegetables fromborers, leafminers and other listed insects.

� For pine beetles use 1 fluid ounce in 1 gallonwater applied as a thorough spray, wetting theleaves and branches to dripping point. Spray inlate afternoon or evening, when temperatureranges from 50 to 75 degrees F and when thereis little or no wind. Spray at the first sign ofinsects. Repeat as necessary; use at intervals or4 to 8 days. Do not exceed 16 applications perseason.

� For peach tree borers (lesser peachtree, peachtwig) apply 2 fluid ounces in 1 gallon waterwhen insects appear. Wet the plants to drip-ping point. Do not apply within 7 days of har-vest. Do not make more than eight applicationsper year.

Bonide® Total Pest Control Concentrate OutdoorFormula (13.30 percent permethrin): Warning. Forornamental trees around the home, use sufficientspray to obtain full coverage of all foliage. Avoidheavy wetting. Use to control pine moths and pinebeetles. On peaches to control lesser peachtree borerand peach twig borer: Use 23/4 teaspoons per 5 quartswater. Apply when insects appear. Do not applywithin 7 days of harvest. Do not make more thaneight applications per season.

Spinosad, a spinosyns insecticideFerti.lome® Borer, Bagworm, Tent Caterpillar &

Leafminer Spray (0.5 percent spinosad): Caution.For use on fruiting, tuberous and leafy vegetables,stone fruits, apple and citrus trees, ornamentals and

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lawns: Use 2.0 fluid ounces per gallon for peachtwig borer (a caterpillar of a clearwing moth species)on fruit trees only.

Soil drenchesDinotefuran, a neonicotinoidinsecticide

Spectracide® Tree and Shrub Insect Control +Fertilizer Concentrate (0.43 percent dinotefuran):Caution. Available to homeowners through retailoutlets for roundheaded borers apply 3 fluid ouncesper inch of tree circumference or 9 fluid ounces perfoot of shrub height. Note: For professional use, seelabel for Safari®.

Imidacloprid, a neonicotinoidinsecticide

Marathon® 60 WP (60 percent imidacloprid):Caution. For systemic control on ornamentals ingreenhouses, nurseries and interior plantscapes as asoil injection for flatheaded borers including bronzebirch and alder borers to trees at a rate of 20 gramsper 8 to 16 inches of cumulative trunk diameter or toshrubs at a rate of 20 grams per 8 to 16 feet of cumu-lative shrub height applied as a soil injection or soildrench as directed on the product label. AlsoMarathon® II (21.4 percent imidacloprid), using dif-ferent rate.

Bayer Advanced™ 12 Month Tree & Shrub InsectControl (1.47 percent imidacloprid): Caution. Forflatheaded borers including bronze birch and alderborers apply to the soil as a drench to trees at 1ounce per inch of distance around the trunk and toshrubs at 3 ounces per foot of height.

Discus™ Nursery Insecticide (0.70 percentcyfluthrin plus 2.94 percent imidacloprid): Caution.For ornamentals, nonbearing fruit and nut trees, andin field and container nurseries. Use as a drench andsoil injection application for shrubs, evergreens andtrees including nonbearing fruit and nut trees.

For flathead borers including bronze birch andalder borers, use 3.4 to 5.6 fluid ounces per 1,000square feet. Use at the high rate for borer controland with high populations. Application to heavilyinfested trees may not prevent the eventual loss ofthe trees because of existing pest damage and treestress. Note: Cypermethrin is a pyrethroid contactinsecticide and will not move into the tree systemi-cally.

Tree injection productsAcephate

Acecap® 97 Systemic Insecticide Tree Implants(97 percent acephate): Caution. For ornamental treeswith a trunk diameter of 3 inches or larger for treat-ment of borers. For small trees and shrubs with

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trunk diameters of 1.5 to 3 inches see the label forMini Acecap 97.

Acejet Systemic insecticide for Micro-Infusion™

(97.4 percent acephate): Caution. Micro-Injectableand Micro-Infusable Insecticide for use with theArborjet Injection Systems to manage of specificinsect pests of trees and landscape ornamentals,including conifers, Christmas tree and deciduoustree farms, seed orchards and plantations, and foresttrees, shrubs, evergreens and conifers, and trees inChristmas tree plantations and palms in forest areasincluding nonurban forests, tree plantations, seedorchards, parks, rural shelter belts, rangeland andwoodlands including conifers. For treatment of car-penterworm, clearwing borers, cottonwood twigborer, Nantucket pine tip moth, pine coneworm,pine tip moth, buprestid borers including bronzebirch borer, flatheaded borers, longhorned borersincluding red oak borer, and root weevil adultsincluding black vine weevil. Do not treat trees thatare moisture stressed or suffering from herbicidedamage. Do not inject trees within 2 weeks of anyother spray or soil chemical treatment.

DicrotophosInject-A-Cide B® (82 percent dicrotophos):

Danger. Contains Bidrin®, for internal treatment bymicroinjection for systemic suppression of certaininsects on ornamental trees. Not for use on trees forsale or other commercial use, for commercial seedproduction, for the production of timber or woodproducts, or for research purposes. For dogwoodtwig borer and sycamore borer (American plumborer) on oaks and sycamore, and for lesserpeachtree borer on flowering stone fruit (noncrop).

Oxydemeton methylMauget Inject-A-Cide® (50 percent oxydemeton

methyl): Danger. Internal treatment by microinjec-tion for systemic suppression of certain insects onornamental trees. Treatment limited by tree speciesto treatment of bark beetles on cedar, cypress,juniper and pine; engraver beetles; red and blackturpentine beetles; and Nantucket pine tip moth onDouglas fir and pine.

ImidaclopridIMAjet Systemic Insecticide (5.0 percent imida-

cloprid): Warning. Microinjectable systemic insecti-cide for use with Arbojet Injection System in themanagement of specific insect pests of forests, trees,landscape ornamentals, palms and interiorplantscapes (trees, shrubs and evergreens), palms inforest areas including nonurban forests, tree planta-tions, Christmas tree farms, parks, rural shelter belts,rangelands and woodlands including those withconifers. For treatment of buprestid borers includingbronze birch borer, flatheaded borers, longhornedborers and pine tip moth larvae.

Mauget® Imicide Systemic Injecticide for treeinjection use in ready to use capsules (10.0 percentimidacloprid): Caution. Injection into trees morethan 2 inches in diameter that will not produce foodwithin a year after treatment: Use as directed for

black vine weevil larvae, bronze birch borer, cotton-wood longhorned borer, flatheaded borers includingalder and birch borer, pine tip moth larvae and otherlisted pests. Also see Mauget Imicide Hp for use inloadable injectors.

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