How to treat wood borers in trees

Shade Tree Borers - 5.530

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by W.S. Cranshaw* (1/19)

Quick Facts…

  • Wood borers are insects that develop underneath the bark of trees and shrubs. Certain beetles and moths are the most common borers.
  • Insecticides can best control most shade tree borers if they are applied when adult insects are laying eggs on tree trunks.
  • Most wood borers attack only trees that are stressed due to drought, injury or disease. Consequently, any means of promoting vigorous tree growth should be considered the primary approach for borer management.
  • Certain wood borers, such as emerald ash borer, peachtree borer, and Zimmerman pine moth, are capable of damaging healthy trees.
  • The emerald ash borer, an insect that has only recently found its way to Colorado, is an exceptionally destructive wood borer.
Figure 1: Bronze birch borer laying egg under bark crevice. Phtograph by David Shetlar, The Ohio State University.
Figure 2: Bronze birch borer larva, a type of flatheaded borer.
Figure 3: Emerald ash borer adult next to D-shaped exit hole. Photograph by David Shetlar, The Ohio State University.
Figure 4: Extensive tunneling injuries produced by larvae of the Gambel oak borer. Photograph by David Leatherman.
Figure 5: Mating pair of locust borers, a type of longhorned beetle.
Figure 6: Locust borer larvae (roundheaded borers) and tunneling of black locust.
Figure 7: Poplar borer, a common borer of aspen.
Figure 8: Poplar and willow borer, a type of weevil that develops as a borer in the stems of willows.
Figure 9: Larva of the peachtree borer. On the underside are several pairs of prolegs, tipped with an oval rig of small hook. That presence of prolegs distinguishes the borers that develop into moths. Phtograph by David Shetlar, The Ohio State University.
Figure 10: Damage to the base of an ash tree produced by lilac/ash borer.
Figure 11: Adult male of the peachtree borer, a type of clearwing borer.
Figure 12: Pupal skin of the lilac/ash borer remaining extruded from the trunk after the adult emerged from the tree.
Figure 13: Larva and damage by the pinyon pitch mass borer.
Figure 14: Adult of the Zimmerman pine moth. Photograph by David Shetlar, The Ohio State Univerrsity.
Figure 15: Larva of the carpenterworm.
Figure 16: Adult of the carpenterworm. Photograph by David Leatherman.
Figure 17: Adult of the pigeon tremex.
Figure 18: Larvae of the pigeon tremex.

Several kinds of insects develop by tunneling in some manner within the branches, trunks or roots of trees and shrubs. The largest number of these are known as wood borers, which include various beetles, moths and an odd family of wood boring wasps (horntails).

Most wood borers lay their eggs on the bark and the immature stage (larva) that follows chews into the plant to feed, tunneling or gouging areas within the plant as it develops. When they have completed their development, typically in one to two years, they transform to the adult form which then emerges from the plant to mate and lay the eggs that produce the next generation.

Some wood borers can seriously damage plants, by cutting through tissues that move water and nutrients or through significant structural weakening. Examples of these more “aggressive” wood borers that occur in Colorado would include peachtree borer, Zimmerman pine moth and emerald ash borer. However, many wood borers cannot successfully attack healthy plants. These will only be found in plants, or parts of plants, which have been previously damaged by wounds, infected with canker producing fungi, or are severely stressed due to recent transplanting, drought or root injuries. Most of the more common wood borers that occur in Colorado are included in Table 1.

Types of Wood Borers

Metallic Wood Borers/Flatheaded Borers (Coleoptera: Buprestidae)

The beetle family Buprestidae are known as both metallic wood borers and flatheaded borers, terms that refer to the adult and larval stages of these insects, respectively. The adults (metallic wood borer) are elongate-bodied beetles that have a metallic sheen. Most metallic wood borers are green, bronze or blue, but brightly colored species also occur. The adults feed on leaves of host trees and shrubs and females lay eggs in crevices of the bark. The larva that occurs within the plant (flatheaded borer) is pale colored with dark jaws, often very elongated, and has a flattened area behind the head.

Flatheaded borers feed just under the bark, making meandering mines through the cambium, phloem, and outer xylem tissues of the plant. These wounds restrict movement of nutrients in the plant which may result in a progressive thinning of the leaf canopy. On the trunks and limbs there is little or no evidence of infestation, but when adults emerge from the plant they chew a distinctive D-shaped exit hole. Flatheaded borers typically take a year to complete development. Flatheaded borers that commonly cause plant injuries include emerald ash borer, bronze cane borer, bronze birch borer, and flatheaded appletree borer.

Longhorned Beetles/Roundheaded Borers (Coleoptera:Cerambycidae)

The beetle family Cerambycidae are known as both longhorned beetles and roundheaded borers, terms that refer to the adult and larval stages of these insects, respectively. The adults (longhorned beetles) are named for the very long antennae typical of the adult. They are medium to large beetles that are usually brown or gray, but some have bright patterning. When laying eggs the adult will first chew a small pit and then insert the egg underneath the bark. The larva that occurs within the plant (roundheaded borer) is pale colored with a dark jaws and has an elongated body that is generally round in cross-section.

Roundheaded borers will initially feed in area around the cambium but most will later borer deeply within the plant. The tunnels produced are oval in cross section and they may cause significant structural weakening of the plant. In late stages the larvae may make an opening on the trunk and expel sawdust, which is often coarse and stringy. When adults emerge from the plant they chew an oval-shaped exit hole. A generation may be completed in a year, but some species take 2 or more years to develop. Most roundheaded borers are only found in trees that are in serious decline or have been recently cut or killed. However there are a few species, such as poplar borer in aspen and locust borer in black locust, which can seriously damage live trees.

Weevils (Coleoptera: Curculionidae)

The beetle family Curculionidae, known as weevils, contains a great many species in Colorado by only one is a wood borer of note, the poplar and willow borer. It is almost always found in small diameter (1 to 4 inch) trunks with shrubby willows being the most common hosts. Infestations are often indicated by the presence of a coarse sawdust-like excrement that plugs the exit hole.

Clearwing Borers (Lepidoptera: Sessiidae)

Moths in the family Sesiidae are known as “clearwing borers”.  This refers to a feature of their wings, which are largely absent of the scales that cover wings of most moths and butterflies. They have an overall appearance that resembles a wasp or bee, although they are harmless. Because they are such close mimics of stinging insects, clearwing borers can largely avoid attacks by birds and are one of the few moths that fly during the day. Eggs are laid on the surface of the bark.

Most all larvae of clearwing borers develop in either the lower trunk or upper roots of the plant and many are referred to as “crown borers” since they concentrate feeding in the upper root crown. Clearwing borer larvae are pale colored, with dark jaws and have an overall appearance somewhat similar to a roundheaded borer. However, they are distinguished by having five pairs of very short leg-like structures (prolegs) on the underside of the abdomen, each marked with a series of tiny hooks (crochets).

Clearwing borer larvae concentrate feeding in areas under the bark, making large gouging wounds. More extensive tunneling may also occur in the interior of the lower trunk. When full grown they will excavate an area just underneath the bark and chew into the bark so that only a paper-thin area remains. They then transition to the pupal stage positioned just underneath this opening. When the adult moths are ready to emerge, they wriggle to push through the bark, pulling the pupal case through the opening. After the adult moths extract themselves, the pupal case often will remain extruded from the plant or drop to the base of the plant.

Development (egg to adult) of all requires a year to complete. Many clearwing borers can seriously damage even healthy plants. Significant species in Colorado include lilac/ash borer, peachtree borer, and currant borer. Fact Sheet 5.566 Peachtree Borer and Fact Sheet 5.614 Lilac/ash Borer: A Common Wood Borer of Colorado’s Street Trees provides more details on these species.

Pyralid Borers (Lepidoptera: Pyralidae)

The moth family Pyralidae contains a great many species, but only a very few are wood borers. In Colorado, two species occur both of which attack pines – pinyon pitch mass borer and Zimmerman pine moth.  Both develop in the trunks or larger branches of their host plants, producing large gouging wounds under the bark. A large amount of pitch oozes from and covers these wounded areas. The larvae are pinkish or gray and possess five pairs of short prolegs on the abdomen, each of which is tipped with a circle of fine hooks. More information on Zimmerman pine moth is found in Fact Sheet 5.591 Zimmerman Pine Moth.

Carpenterworms (Lepidoptera: Cossidae)

The moth family Cossidae are known as carpenterworms.  Adults are very large moths and the larvae grow to be very large caterpillars that tunnel deeply into trunks. The most common species, known as the carpenterworm (Prionoxystus robiniae), can develop in a wide variety deciduous trees, but is most often found in cottonwoods and poplars. The life cycle of the carpenterworm is unusually long for a wood borer, taking 3-4 years to complete. Appearance of carpenterworm larvae is somewhat similar to those of clearwing borers.

Horntails (Hymenoptera: Siricidae)

Horntails are a family (Siricidae) of nonstinging wasps that develop as wood borers within trunks and branches of dead or dying trees. Several species are present in forested areas that attack recently killed or cut pines. Only one species, known as the pigeon tremex (Tremex columba), attacks deciduous trees, such as ash, elm, and maples. The pigeon tremex, and a primary natural enemy of the insect, are covered in Fact Sheet 5.604 Pigeon Tremex and the Giant Ichneumon Wasp.

Horntails are incapable of attacking trees in good condition and the pigeon tremex will only develop within trees that are in the very end stages of decline and have low moisture content. However, horntails may slightly accelerate ultimate tree death by introducing white rot fungi into trunks, which are introduced with the aid of their long ovipositor that is used to insert eggs into the wood. (The decay produced by white rot fungi can also structurally weaken the wood.) When adult horntails emerge from the trees they cut a circular emergence hole about the diameter of a pencil.

Wood Borer Management

Promote host plant resistance

All trees have some ability to defend themselves from attacks by wood borers. Defensive chemicals are produced in response to borer wounding that may weaken and kill young borers. Callus tissue growth may be stimulated by wounding and encapsulate young borers. Trees that are well hydrated also become less suitable for attack and in the case of conifers may produce large flows of resin that can drown an invading insect. The intensity of all of these tree defenses is related to tree condition, particularly the amount of energy reserves that had been stored by the plant and the level of water stress.

Consequently, any means of promoting tree health should be considered the first approach for managing most borers. This begins with the proper selection of trees and shrubs that are well adapted to the site; poorly adapted plants may be particularly susceptible to borers. Plants should also be well pruned, eliminating damaged or overshaded limbs. Providing adequate moisture to the roots by timely irrigation and/or use of suitable mulches can be extremely important in limiting damage by many borers.

However, there are a few kinds of borers in Colorado that may not be well controlled by tree defenses alone. The best example of an “aggressive borer” that is capable of killing healthy trees is emerald ash borer, a newly established insect of Asian origin that is presently (2018) found in parts of Boulder County. Peachtree borer, Zimmerman pine moth, and locust borer are other borers that may seriously damage trees in good condition.

Preventive insecticide bark sprays.

With very limited exceptions it is not possible to control wood borer larvae that have already entered the plant where they become well protected. However, all wood borers will emerge from the tree or shrub when they reach the adult stage and become vulnerable to treatment. At this point insecticides sprayed onto the trunks can kill adults as they crawl on the bark and very young borers that emerge from eggs laid on the surface. This can prevent damage that could be produced by the next generation of the insect.

The types of insecticides that are effective for this purpose have fairly long persistence when applied to bark and should be capable of killing wood borers for several weeks. Presently three insecticides applied as bark sprays are used for control of wood borers: bifenthrin, permethrin, and carbaryl (Table 1).

The optimal timing for preventive trunk sprays is at about the time when the adult stages of the wood borer are first present. For some species, such as the lilac/ash borer, adults emerge and begin to lay eggs in mid to late Spring. Others emerge later and some only first become active on the outside of the plant beginning in midsummer. A summary of some of the more common wood borers, and their period of adult activity (flight period), is in Table 2.

Preventive trunk sprays are the easiest and cheapest means to effectively control almost all borers. A notable exception is emerald ash borer, the most aggressive and damaging wood borer in Colorado. Emerald ash borer is best controlled by use of certain systemic insecticides applied to the soil or as trunk injections.

Soil-applied systemic insecticides

The insecticide imidacloprid can move systemically within plant. When applied as a soil drench over the roots of a tree or shrub and watered into the soil imidacloprid can be used to control some kinds of wood borers.

The kind of borers that can be most effectively controlled by imidacloprid are flatheaded borers.  These are a kind of beetle larva that feed in areas under the bark where imidacloprid will move in sufficient concentration to kill susceptible insects.

It will take some time for imidacloprid to be taken up by the plant, often 2-3 weeks.  Therefore it is best applied around the time when the insects are beginning to lay eggs, or a little before. Critical to the use of this method is that the soil is kept moist enough for the insecticides to move to the roots. Systemic insecticides applied to dry soil will not be effective.

Many borers are not well controlled by soil applications of imidacloprid. Beetle larvae that spend much of the time in the interior of the trunk, such as roundheaded borers, will be little exposed to the insecticide. Imidacloprid is also not effective against larval stages of moths, such as clearwing borers, carpenterworms and pyralid borers.

Soil applications of imidacloprid can result in movement of some of the insecticide into nectar.  This can then be collected by bees and other flower visiting insects. Therefore the use of this insecticide for borer control is discouraged on plants that produce flowers that are attractive to bees. (Lindens, crabapples, plums and some cherries are is a good examples of trees heavily visited by bees.) Strong language is present in the label instructions of most imidacloprid products and these must be followed to avoid risks to pollinators.

Trunk sprayed systemic insecticides

Insecticides containing the active ingredient dinotefuran (Safari, Transtect, Zylam) can be applied to the trunks and will then move systemically within the tree. These applications can be effective for control of wood boring beetles (metallic wood borers, longhorned beetles). There is insufficient information to know if these treatments can be reliably effective against wood borers that are caterpillars (Lepidoptera).

Dinotefuran trunk sprays may move more rapidly into trees than are insecticides used in soil application. Optimal time of application for borer control can be around the time of first expected adult emergence and egg laying or for a month or two after that period.  However, on trees that produce flowers that are attractive to pollinators applications should be applied only after flowering, since this insecticide can move into nectar. Trunk spray applications require considerable expertise and should only be made by licensed pesticide applicators.

Trunk injected systemic insecticides

Some insecticides can move systemically in plants but must be physically injected into trunk. The most common insecticide used for this purpose is emamectin benzoate. Azadirachtin, a naturally derived product from seeds of the neem tree, can also control some borers when trunk injected. Both of these are presently used frequently in Colorado to control emerald ash borer.

Trunk injections require specialized equipment and considerable skill to be used effectively and not cause undue wounding. These can only be done by trained pesticide applicators and are often far more expensive than trunk sprays. However, the insecticides used for trunk injections can control most kinds of wood borers and emamectin benzoate may provide reliable control for 2 or 3 years. Trunk injections also become more attractive when there are conditions at a site that prevent use of sprayed or soil-applied insecticides.

Related Extension Fact Sheets

  • Fact Sheet 5.566 Peachtree Borer
  • Fact Sheet 5.614 Lilac/ash Borer: A Common Wood Borer of Colorado’s Street Trees
  • Fact Sheet 5.591 Zimmerman Pine Moth
  • Fact Sheet 5.604 Pigeon Tremex and the Giant Ichneumon Wasp

Resources Related to Emerald Ash Borer

  • Colorado Department of Agriculture Emerald Ash Borer Website
Table 1.   Insecticides used to control wood borers in trees and shrubs
Insecticides used as preventive trunk sprays
Active ingredient Trade name(s) (retail) Trade name(s) (commercial application) Comments
permethrin Hi-Yield Turf, Termite and Ornamental Plus1 Astro, Permethrin, others Label allows use on many fruit trees
bifenthrin None1 Onyx, Talstar No label uses for food crops
carbaryl None1 Sevin SL, Carbaryl 4L Use allowed on most all fruit crops
Systemic insecticides used as a soil drench
imidacloprid Bayer Advanced Tree & Shrub Protect and Feed Concentrate II2, Bonide Annual Tree and Shrub Control, ferti-lome Tree and Shrub Insect Drench, Bug-b-Gon Year-Long Tree & Shrub Insect Control Merit, Mallet, Zenith, others Only effective against flatheaded borers. Some restrictions for use on plants that produce flowers and are visited by bees.
dinotefuran None Safari, Transtect, Zylam Effective against flatheaded borers and roundheaded borers; not recommended clearwing borers. Do not apply prior to bloom on plants that produce flowers that pollinators visit.
Systemic insecticides used as a trunk spray
dinotefuran None Safari, Transtect, Zylam Applications are made as a coarse spray to lower trunk. Effective against flatheaded borers and roundheaded borers; not recommended clearwing borers. Do not apply prior to bloom on plants that produce flowers that pollinators visit.
Systemic insecticides used as a trunk injection
emamectin benzoate None3 Tree-AGE, Arbormectin, Boxer Can provide control for 2-3 years. May be effective against all types of common borers.
azadirachtin None3 TreeAzin, AzaSol, AzaGuard, others Naturally-derived insecticide. May be effective against all types of common borers.
1 Carbaryl, bifenthrin and other permethrin containing products are sold at retail stores but label instructions do not allow use rates that are effective for wood borers.
2 Also contains the insecticide chlothianidan.
3 Requires specialize equipment and can only be applied by commercial applicators.
Table 2: Flight periods and hosts of common shade tree borers in Colorado.
Common Name Common Hosts Typical Flight periods
METALLIC WOOD BORERS (Coleoptera: Buprestidae)
Flatheaded apple-tree borer
Chrysobothrus femorata,
Apple, maple, oak, other hardwoods June-August
Chrysobothris texana Junipers mid June-early August
Emerald ash borer
Agrilus planipennis
Ash late May-early August
Bronze birch borer
Agrilus anxius
Birch June-July
Honeylocust borer
Agrilus difficilis
Honeylocust June-July
Bronze poplar borer
Agrilus ligarus
Aspen, other Populus June-August
Bronze cane borer
Agrilus cuprescens
Raspberry, currant, rose late May-June
Gambel oak borer
Agrilus quercicola
Oak early June-late July
LONGHORNED BEETLES (Coleoptera: Cerambycidae)
1Cottonwood borer
Plectodera scalato
Willows, poplars, cottonwoods July-August
1Locust borer
Megacyllene robiniae
Black locust (Robinia) August-September
Poplar borer
Saperda calcaratar
Populus, willow June-August
Redheaded ash borer
Neoclytus acuminatus
Ash, fruit trees, other hardwoods April-June
Pine sawyers
Monochamus species
Pines, spruce, fir May-October
Blackhorned pine borer
Callidium antennatum
Pines May-June
WEEVILS (Coleoptera: Curculionidae)
Poplar and willow borer
Cryptorhynchus lapathi
Willow, poplar July-August
CLEARWING BORERS (Lepidoptera: Sesiidae)
Lilac/ash borer
Podosesia syringae
Ash, lilac, privet April-June
Cottonwood crown borer
Sesia tibialis
Cottonwood mid June-July
Peachtree borer
Synanthedon exitiosa
Prunus mid June-late August
Currant borer
Synanthedon tipuliforme
Ribes late May-June
Viburnum borer
Synanthedon viburni
Viburnum June-July
CARPENTERWORMS (Lepidoptera: Cossidae)
Prionoxystus robiniae
Elm, maple, ash June-July
PYRALID BORERS (Lepidoptera: Pyralidae)
1Pinyon pitch mass borer
Dioryctria ponderosae
Pinyon, ponderosa pine June-August
3Zimmerman pine moth
Dioryctria zimmermani
Austrian, Scots pine August-September
HORNTAILS (Hymenoptera: Siricidae)
Pigeon tremex
Tremex columba
Maple, elm, ash, other hardwoods late July-August
1 Life cycle often takes 2 years to complete.
2 Life cycle takes 3-4 years to complete.
3 Larvae remain on bark and exposed to treatment until late April.

*Colorado State University Extension entomologist and professor, bioagricultural sciences and pest management. 10/99. Revised 1/19.

Colorado State University, U.S. Department of Agriculture, and Colorado counties cooperating. Extension programs are available to all without discrimination. No endorsement of products mentioned is intended nor is criticism implied of products not mentioned.

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How to Get Rid of Tree Borers and Prevent Infestation

Also known as tree borers, wood borers feed on and make habitats from trees and other woody plants. They belong to a variety of insect groups, including beetles, wasps, and moths, and are often the larva of these species.

Wood-boring insects fall into two categories — primary and secondary invaders.  

Most tree borers act as secondary invaders, meaning they attack weakened, dying, or dead trees. 

Primary invaders target healthy plants, which can lead to them weakening, or dying. With a proactive approach to handling wood-boring insect infestation, you can defend your trees from both kinds of pests.

  • See How to Prevent Tree Borer Infestations

Common Types of Tree Boring Insects

The types of borer that could infest your trees depend on your region in the United States. Wood-boring insect species also attack different varieties of trees and bushes, so your plants may be more prone to certain borers than others. Some of the most common types of wood borers include:

  • Flat-headed wood borers: Also called jewel beetles or metallic wood-boring beetles. This large family of beetles attack stressed or recently transplanted trees.
    As adults, these borers have unique metallic colors and a boat-like shape, with larvae having a similar flat appearance.
    Because of this body shape, the larvae create oval or flattened holes when they dig into wood. The tunnels that these insects create can girdle tree trunks and branches, putting trees at severe risk. 
  • Round-headed borers (longhorn beetle): In their adult form, round-headed borers are longhorned beetles that can have antennae longer than their bodies. The larvae of round-headed borers have a round shape that leaves behind a round or oval tunnel. A tree afflicted with a round-headed borer infestation will often have signs of dust-like frass (excrement) or sap on the trunk and branches. Most of the insects in the round-headed borer category act as secondary invaders.
  • Weevils: In contrast to borers that create galleries or tunnels in wood, weevil larvae dig hollowed-out cavities or cells underneath bark. Many weevil species target the roots and bases of woody ornamental plants.
  • Wood-boring moth caterpillars: Also known as clearwing borers because of their adult form as clearwing moths, wood-boring caterpillars hatch in tree bark after an adult lays eggs there. They immediately burrow into the bark after hatching to feed on the wood. Once the larvae tunnel into the wood, insecticide sprays won't affect them. Clearwing moths can sense the chemicals released by stressed or damaged trees and seek them out as egg-laying sites.

Photo Credit:


Effects of Borer Damage to Trees

Borer-related tree damage has a few distinct signs, and it can become deadly for already-weakened trees. Since the boring occurs inside of the tree, many infestations go unnoticed until external signs of damage appear. If you notice any symptoms of tree borer infestation, act as soon as possible to prevent further damage.

To assess possible damage, keep an eye out for the following signs:

  • Tunnel holes: One of the telltale signs of a tree borer infestation is the holes created from borer tunneling. Depending on the species of borer, these tunnels may have round, semicircular, or oval shapes. Borer holes tend to appear in a random pattern on the bark, contrasting with the neat rows created by a woodpecker.
  • Frass: You can tell borer holes apart from woodpecker holes by looking for frass, the excrement that borers create as they feed on wood. Frass looks like sawdust, and you can find it inside the holes or just outside of them.
  • Dead limbs or cracked bark: Wood borers tunnel in the cambium, the inner layer of tree bark that transports water and nutrients. As pests erode the cambium, the areas of the tree above the damage receive fewer nutrients. This lack of nutrition can cause the bark to crack or the connected tree limbs to die and fall off.
  • Oozing sap (gummosis): A stone fruit tree will have gummosis, sap oozing from its wounds, during a borer infestation. If borers dig into sap-producing parts of the wood, the sap flows out of the tunnel. You may also see frass in the oozing sap.


Tree Borer Treatment and Management

If your tree has a wood borer infestation, you can use one of two methods to kill the tree borers:

  • Chemical: Depending on the type of borer infesting your tree, you can use contact insecticide and soil treatment to kill active borers and prevent future infestations. Every state has its own standards on pesticide use, so make sure you can legally use a pesticide before applying it to your trees.
  • Mechanical: Outside of using pesticides, your possible management strategies involve removing the larvae from the tree with a tool or getting rid of infested wood. If you have a severe infestation, you may need to clear the entire tree to eliminate the risk of falling branches.

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Preventing Tree Borer Infestations

The best way to handle a wood borer infestation is to stop it before it begins. Consider these methods of preventing tree borers from attacking:

  • Proper tree care: Since borers target weakened or stressed trees, you can lower the risk of infestation with correct watering and fertilization techniques. Remember to pay careful attention to newly transplanted trees with a higher risk of stress.
  • Choosing the right tree species: When planting new trees, select species that wood borers in your area don't often attack. Research the less susceptible trees in your region and focus on them instead of more vulnerable varieties.
  • Preventing and caring for tree injury: External damage from equipment like mowers can leave a tree open to borer infestation. If you accidentally damage a tree, take care of the wound using pruning or wound paint as soon as possible.


Wood Borer Control Solutions from Diamond Mowers

When you can only get rid of tree borers by removing the infected tree, we suggest using one of our
American-made skid-steer or excavator attachments.  

We offer a wide range of attachments for clearing trees and brush, mulching, and grinding stumps so you leave no food behind for borers. 

To learn more about our products and how to use them for invasive species management , visit a Diamond dealer near you or contact our attachment experts.

Topics: Skid-Steers & Attachments, Application: Forestry, Excavators & Attachments, Invasive Bugs/Insects

Treatment of trees from bark beetle, how to save a tree from bark beetle

This type of pest feeds on wood. It is quite difficult to see beetles on young healthy trees. Ephedra, when trying to be colonized by parasites, secrete resin, stone fruit - sticky gum, which clog all cracks, literally drown insects and prevent lesions from developing. But if the “food source” is weakened or the environment around it is favorable for population growth, you will have a long struggle with bark beetles and treatment of plantings.

Insect ambulance

When the sum of positive temperatures from the beginning of the year reaches 140-150 degrees, the first flight of a printer operating in spruce forests begins. Then in mid-May comes the turn of fruit sapwood in the gardens.

Each tree has its own bark beetle and, if no measures are taken, after a while they will settle everywhere, begin to multiply and devour the bark, sapwood, branches. With a fairly warm winter in the spring, expect an invasion. It is very difficult to save an infected area. Often, the only remedy for treating a tree from a bark beetle is the Friendship saw.

To prevent this from happening, you need to act before the appearance of insects. To create effective protection, you will need to remove all debris from the site, remove or burn dead wood, old leaves, stumps, cut down diseased trees, and cut dried branches. A mandatory measure is spraying, which is carried out before the flowering of fruit crops.

If there are no ready-made insecticides on hand, you can use a home-made product from an aqueous solution of liquid soap and carbolic acid (for 5 liters of water, 2 cups of other ingredients). Before use, the solution is diluted with water (1:4).

When planting young vegetation, pest control must be carried out immediately. This can be a simple remedy from a one percent solution of karbofos, which is sprayed on the trunks from bottom to top. If the beetle has already arrived, spray again, making sure that the drug does not fall on the leaves.

Drill dust on a tree at the beginning of the season is a sure sign that insects are already nesting inside the trunk. If this fate befell one or two cultures, try to make an incision on the bark above the hole and move it to the side. There you will find the whole family. Without thinking about how to save the tree from the bark beetle, start manually cleaning the passages with a sharp knife.

Inspect the entire barrel and perform the procedure on all burrows found. This is a long and painstaking business, but there is a chance that you will be able to cure the planting. After hunting for a beetle, treat the surface with karbofos or chlorophos and pour it with an immunostimulant (for example, Zircon). The next watering and spraying should be done in 5-7 days and repeat this for a month.

Treat or remove?

To understand how to act, you need to assess the degree of damage. It is possible to cure a tree from a bark beetle only at the initial stage of the disease.

When insects have just settled, it is worth trying to save an apple tree or other fruit crop. If the holes on the trunk were found only at the end of August, do not rush with treatment. The new beetles have already flown out, leaving shattered wood in their wake. And although while the crown is still green, the vegetation most likely cannot be saved, since the structure and sap flow are disturbed. Numerous passages with exfoliating bark are the first sign of death. In this case, only removing the tree and destroying it will help.

Treatment requires a whole range of measures aimed at:

  • elimination of mechanical damage - cracks, hollows, cuts;
  • pest control - treatment with chemical and biological preparations, installation of repellers;
  • strengthening the immunity of vegetation - immunostimulants, top dressing with fertilizers;
  • removal of centers of reproduction of beetles - cutting down and destruction of diseased and weakened plantings;
  • tree protection.

Only then will the result be effective.

When an infestation is detected, spraying with insecticides (Kliper, Confidor, Decis, Aktara and others) or biologically active preparations based on nematodes can be used. Moreover, both types of funds are not used simultaneously.

Intra-stem injections have proven themselves well, which spread along the entire stem with sap flow and have a paralyzing effect on the central nervous system of insects. They stop eating, moving, reproducing, and eventually die. You can inject the funds directly into the gnawed passages or enter them with special devices under high pressure through the holes made.

After the procedure, the holes are closed with special plugs to protect against the ingress of germs and bacteria. Over time, the cork overgrows with new bark.

The drugs used can be different, both professional (Arbojet, Mauget) and well-known:

  • Antizhuk;
  • Confidor;
  • Calypso;
  • Empire20;
  • Antishashelin.

Funds are introduced several times (from 2 to 4), after which the passages are smeared with garden pitch. If the treatment of trees is not possible, they are removed and burned to prevent the spread of insects around the site.

Do not try to save weak and diseased stands. It is also better to remove them from the site, since they will be the first contenders for colonization by bark beetles.

Pest control, immunostimulants, intra-stem injections, pruning and removal of affected parts and entire trees - this is all in the arsenal of professional arborists, without whose help you cannot do without. Spraying is carried out using modern equipment (fog generator), which provides instant action and good penetration; special low-impact devices are used for injections. All drugs are absolutely safe for humans and can cure green spaces.

ways to fight. How to deal with carpenter beetles and how to prevent their appearance. Types of woodworm beetles, ways to combat parasites, preventive measures.

May 26 • Helpful Hints, Plot • 3939 Hits • 1 Comment on Wood Borer Beetle: How to Control it

Wood Borer Beetles are a serious threat to wood and everything made from it. Such pests infect home furniture, plants in the garden, walls of log cabins and other structures made of wood. In this article we will tell you what woodworm beetles are and how to get rid of them.


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  • How to detect beetles in wood
  • How to deal with wood ramps
    • Folk remedies
    • Insecticides from the beetle
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  • How to fight a bustle of the DRIVOTRA. Video

Wood beetle species

There are several varieties of insects that can be attributed to the concept of carpenter beetles. Let's take a closer look at what these pests are:

  1. The brown barbel, also called the black barbel or house lumberjack, is an insect that most often infects coniferous trees. The barbel brownie loves dryness and warmth, so its females begin to actively breed in the summer, laying larvae under the bark of coniferous trees. It is worth noting that these beetles are almost impossible to find in living trees, since they do not tolerate moisture. But if you have boards prepared or there are any items made from conifers on the farm, this parasite can harm them. It is not difficult to recognize these insects, in the course of their life they leave winding passages in the wood. Affected objects may be covered with a white powdery coating. The mustachioed brownie most of all likes coniferous bark, so when harvesting wood, even small fragments of bark should be carefully removed from the trunks.
  2. Pseudo-beetle, also called the hood beetle, is another type of woodworm beetle. These insects often live in latitudes with a warm climate, and they can infect almost any wood, easily coping even with durable oak boards. As a rule, false bark beetles gnaw their way along the fibers of the material, making the wood brittle. Such pests can most often be found on support poles, fences, in wells.
  3. Weevil beetles are dangerous because they infect not only dead wood, but also living trees. Such insects prefer a humid environment, so traces of their destruction can be observed among firewood lying in damp logs or directly under the open sky. To avoid damage to the walls of wooden dwellings, baths or sheds, try to store firewood as far as possible from such buildings. Fruit trees should also be protected from the weevil, otherwise you may lose both young seedlings and adult plants.
  4. The borer beetle gets its name from the characteristic marks it leaves in the wood. The diameter of its moves is quite significant and is approximately 1-2 mm. An interesting fact is that the food for such a pest is not the wood itself, but the mycelium that grows in the channels he has made. The favorite species of the parasite are oak and walnut. Fortunately, these trees are not used as the main building material in the construction of log cabins, but the first crown of buildings, as a rule, is made from oak trunks. Among other things, the drill beetle often infects conifers, and especially their bark. If conifers grow on the site, they must be periodically treated with the necessary insecticides.
  5. One of the most common types of pests is the grinder beetle. You can meet this woodworm beetle both at home, for example, in wooden furniture, and in the walls of street buildings. This parasite even eats the wood of living plants, making it a dangerous garden pest. The female grinder beetle lays its eggs in dead or dying wood, the insect likes high humidity and actively breeds in the northern walls of log cabins. It is almost impossible to notice the affected boards or trunks, since the beetles eat away their central part, leaving the outer shell intact. Experts can determine the presence of a grinder in wood using electronic stethoscopes. The device picks up the sound signals that males give to females in order to attract their attention for procreation.

How to find beetles in wood

The destruction of woodworms should begin with their detection. Let's look at what signs you can recognize the affected tree:

  1. Winding passages may be observed on the surface and inside the material. In the course of their activity, the beetles leave drilling flour, which looks like a yellowish or brown powder. As a rule, if the bark is damaged, this substance will have a light shade, and if the deep layers are disturbed, the drilling flour will be dark.
  2. From the passages drilled by woodworms, a brown liquid is released, which has a sharp sour smell.
  3. Affected and dried bark is easily separated from the tree trunk.
  4. Caterpillars can be observed directly under a wooden structure or plant crawling onto another object.

The detection of parasites in the walls of a building or in furniture indicates that it is time to immediately begin to eliminate insects. If a wooden object is of no particular value, it is best to burn it in its entirety, or cut and burn only the affected part. But in the case when this is not possible, you should use special means to treat the tree from beetles.

How to deal with woodworms

Folk remedies

Unfortunately, it is not always possible to notice the affected wood in the early stages. Sometimes the owners of the house do not even assume that parasites have appeared in the walls of their log house, and when the signs of a beetle attack become quite obvious, entire colonies of insects already live in the wooden structures.

Various methods are used to eliminate carpenter beetles. The simplest and most affordable means include:

  1. Salt solution - it is applied to the wood surface in any convenient way. Unfortunately, this method is not very effective, since the product is washed off by rain in a short time.
  2. An aqueous solution of sodium fluoride or silicofluoride with a concentration of 2-2.5% is also an easy-to-prepare composition. This tool is used at the rate of 200 ml per 1 m² of area, treating wood with a brush or spray gun.
  3. Another folk remedy for woodworm beetles is a composition prepared on the basis of resin, black carbolic acid and naphthalene. All components are taken in the same ratio, thoroughly mixed and applied to the wood with a brush.
  4. If parasites have attacked old furniture, the former beauty of which you do not seek to preserve, then try soaking the wood with hot drying oil. But if the furniture is of value, and you do not want to deprive it of its decorative properties, it is better to refuse this method.
  5. Wood is sometimes treated with kerosene, linseed oil, or used motor oil to control pests. You can just paint wooden structures as often as possible.
  6. Another folk recipe involves the use of the following mixture: 3 parts of turpentine are combined with 1 part of kerosene and mixed thoroughly. The wooden surface is treated with petroleum jelly, this composition is poured into the moves made by the bugs, after which the holes are smeared with paraffin.

Most carpenter beetles like moisture, so to prevent pests, it is advisable not to store the wood in damp, unventilated areas, in the open air, or near the northern walls of buildings.

Beetle insecticides

When wondering how to get rid of carpenter beetles, pay attention to special insecticides - insecticides. There are a huge number of such drugs, they can be sold in the form of a powder, gel, or liquid. Powder and gel forms of products are unlikely to effectively cope with the problem, but liquid solutions perfectly penetrate the structure of the tree and etch parasites. So, what subtleties should be considered when treating wood with insecticides:

  1. Residual insecticides are applied to the wood with a spray gun. It is very important that the product gets into all the smallest cracks and the most inaccessible places. Such drugs not only etch pests that are on the surface of the material, but also lure beetles out of their shelters. The advantage of such products is that they are practically harmless to people and animals, therefore, after processing wooden surfaces, residents can return to the premises in a few minutes.
  2. Acute insecticides are considered very toxic to insects and kill them from the first seconds after application. For people and animals, such poisons are quite harmful, so after cleaning the room, you should wait at least 4 hours before returning to it.
  3. Particularly hard-to-reach places should also not be left unattended. For example, preparations in the form of sprays are used to treat the inner surface of floors, but they are not applied at all by spraying. In inconspicuous places, for example, at the joints of boards, small holes are drilled. Then poisonous agents are pumped into them through a thin tube, after which the holes are sealed with wax, paraffin or something else. Insecticides soak the boards over time, killing parasites. After such treatment, it is not recommended to return to the home over the next few days.
  4. The walls of the log cabins, lined with thick beams, are processed in the same way. In the process of work, it is desirable to use preparations with a long duration of action, such agents include, for example, Lignofix I-Profi. If the house has already been attacked by woodworm beetles, you should not spare the time and effort to process it. In each log, you need to drill holes, the depth of which will be equal to ¾ of its thickness. The holes are located every 5 cm above each other, the distance between the rows is 1 m. After the work is done, each hole is filled with an agent against woodworm beetles with a syringe. After absorbing the poison, you need to repeat the procedure 2 more times. Then the holes are covered with a sealed composition.

When thinking about how to get rid of woodworms, take a close look at the industrial products that are on sale. Popular formulations include:

  • Empire 20;
  • Tree Healer;
  • "Antizhuk";
  • Belinka Belocid.

All of the above products have a long period of action, are quickly absorbed into the structure of the tree and destroy the beetles for a long time. When buying an insecticide, read its label. It should contain information that this product is intended to combat flying insects. It is these drugs that destroy not only the beetles themselves, but also their larvae. After processing the premises, you need to leave the house for a while, and you should not light a fire near the processed objects.

How to prevent woodworms

Above, we looked at how to deal with the wood borer beetle, now I would like to pay attention to preventive measures that will help avoid the appearance of parasites in your home. To prevent damage to wood by pests, the processing of the material must be carried out even at the stage of building a house. As preparations for processing logs, such compositions as "Pinotex", "Phoenix", "Senezh", "Lignofix I-Profi" and others are used.

It is also important to ventilate the premises of wooden buildings from time to time. The surfaces themselves should be kept clean, periodically carrying out wet cleaning using "Polish", "Gloss", monochloramine and other similar products. Wooden structures should be regularly opened with varnish or paint, and those surfaces that should remain in their original form should be covered with a thin layer of vaseline oil from time to time.

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