John Jackman

Earwigs

September 28, 2017 by

Dale A. Mott and John A. Jackman*
*Extension Assistant—Integrated Pest Management, and Professor and Extension Entomology Specialist, The Texas A&M University System

Earwigs are one of the most readily recognized insects in the home and landscape. They are abundant throughout Texas and can be a nuisance when they invade homes.

Although earwigs are rarely harmful to people, the insects’ large, pincher-like abdominal appendages, called forceps, can present a formidable appearance. Because of their flattened bodies, earwigs can enter homes through very small cracks. However, they are accidental invaders and generally do not reproduce indoors.

A few earwig species cause some damage by feeding on crops and ornamental plants, but most play a beneficial role by feeding on other insects. Some species emit a foul-smelling, yellowish-brown liquid from their scent glands. However, the most common complaint against the earwig is its mere presence in homes and apartments.

The earwig’s name comes from a European superstition that the insect would enter the ear of a sleeping person and bore into the brain.

Biology and habits

Earwigs are medium-sized insects ranging from 1⁄4 to 1 1⁄4 inches (5 to 31 mm) long and are flattened from top to bottom. Their color ranges from brown to black; some species have yellow or buffcolored stripes or a reddish coloring on the head, body and legs.

All earwigs have a pair of hardened forceps that protrude backward as a tail. Used for defense, the appendages vary among species and from male to female.

Adult earwigs also have a short, leathery pair of wings. A second pair of membranous wings may be folded underneath the first pair.

Earwigs have chewing mouthparts, which they use to catch and eat insects. Earwigs feed at night, and their diet is highly variable. Most species prey on other insects — dead and living — and supplement their diet with various forms of decaying organic matter. They may also feed on mosses, lichens, algae, fungi and more. Indoors, they may feed on houseplants or sweet, oily or greasy foods.

Earwigs are considered temporary pests in landscapes and gardens even though they sometimes occur in high populations. They may feed on foliage of various landscape and garden plants and other plants in the area. If populations are high, they can cause serious damage by feeding on flowers, fruits, vegetables and other plants, giving the leaves a ragged appearance with many small, irregular holes.

Earwigs develop with a simple metamorphosis from egg to nymph to adult. The immature forms look much like the adults but are grayish and lack wings and large forceps.

Females lay from 20 to 300 eggs, usually in a chamber in the soil. The female guards the eggs and newly hatched young. Two generations are produced each year.

Earwigs prefer high moisture and migrate indoors during periods of prolonged heat and drought to seek cool, moist hiding places. During the winter they can dig into the ground as deep as 6 feet to escape freezing temperatures.

About 20 species of earwigs live in the United States. Of those, about 10 occur in Texas, although only three or four are an occasional problem in homes. They are the ringlegged earwig, Euborellia annulipes (Lucas) (Fig. 1); the riparian earwig, Labidura riparia (Pallas); the linear earwig, Doru lineare (Eschscholtz); and the brown-winged earwig, Vostox brunneipennis (Serville).

Management

Figure 1. Ring-legged earwig, Euborellia annulipes (Lucas)
(Dermaptera: Carcinophoridae). Photo by Bart Drees

Three types of control methods are used to manage earwigs in the home or landscape: sanitation, mechanical means and chemical control methods.

Sanitation: Consider modifying the habitat immediately around the house to reduce hiding places for earwigs. Options include:

Remove ornamental stone or excessive mulch (mulch should be 2 to 3 inches deep).
Keep grass and weeds cut short around structural foundations.
Eliminate damp conditions in crawl spaces under homes and outside faucets, near air conditioning units and in other places. Rain gutters and spouts should carry water away from the house’s foundation.
Indoors, seek out and eliminate harborage areas attractive to earwigs, such as leaky plumbing or other high-humidity areas.

Mechanical methods: If only an occasional earwig is found indoors, remove it with a broom, dustpan or vacuum. If you often encounter earwigs indoors, inspect the area to determine how they are entering the structure, and seal up cracks and entry points. Use caulking and weatherstripping around doors, windows, pipes and other places to exclude insects. Because earwigs generally enter the home at the ground level, pay particular attention to low areas.

Trapping can also be used to reduce populations outside the home. Traps such as rolled-up newspaper, corrugated cardboard, bamboo tube or a short piece of hose should be placed on the soil near plants or other sites suspected of hiding earwigs. Check the traps the next morning and shake out any accumulated earwigs into a pail of soapy water. Continue trapping until earwigs are no longer being caught.

Chemical control: Earwigs are easily killed by residual insecticide treatments. Focus your chemical control efforts on the outdoors because that is where the problem originates.

Use insecticides outdoors in a 3- to 5-foot band around the structure next to the foundation (perimeter treatment) to stop or limit earwigs from getting indoors. Areas to treat should include flower beds and sub-floor crawl spaces. Although sprays and granules are effective, you need to wash them into the soil with water, as earwigs can move far into the ground.

You can make these residual insecticides more effective against earwigs by applying them in the early evening, which is just before the time of day that earwigs become active. Also, applying residual insecticides in late spring and/or early summer may reduce populations that would otherwise develop through the summer and into fall. Products such as insecticidal soaps or treatments containing carbaryl, cyfluthrin, permethrin or tralomethrin are effective outdoors.

Using chemicals indoors will not solve the problem of earwigs entering the building and should be used only as a supplement to outdoor efforts. Boric acid or aerosol insecticides labeled for indoor use are effective when used around baseboards, carpet edges, door and window frames and other hiding places.

Regulations change often regarding insecticide use, and changes may have occurred since this publication was written. The pesticide users are responsible for the effects of pesticides on their own plants or household goods as well as problems caused by drift from their property to other properties or plants. Always read and follow carefully the instructions on the container label.

To view photographs of an earwig and many other insects, see http://entomology.tamu.edu

Armyworms in Texas Pastures and Lawns

September 27, 2017 by

Chris Sansone, Rick Minzenmayer and John Jackman

Armyworm outbreaks are difficult to predict but infestations seem to occur in portions of the state every year especially after rains in the early fall. Common species of armyworms present in Texas include: the fall armyworm, Spodoptera frugiperda; the yellowstriped armyworm, Spodoptera ornithogalli; the beet armyworm, Spodoptera exigua; and the armyworm, Pseudaletia unipuncta . The fall armyworm is usually the species that causes the most problems in pastures, small grains and turfgrass.

BIOLOGY AND HABITS

All armyworms have four life stages: egg, larva, pupa and adult. Eggs are very small, white, laid in clusters of 50 or more and are covered with grayish, fuzzy scales from the body of the female moth. The eggs are seldom seen in grasses and are usually laid at the base of host plants. Lush plant growth is preferred by the adults for egg laying. Larvae (caterpillars) are very small when they emerge from the egg. Larvae will feed for 2-3 weeks and can be 26-37 mm (1-1.5 inches) long with various color patterns depending on the species. The larvae have five instars (stages when molting occurs) and sometimes hide in debris on the soil surface in the middle of the day. When full grown, larvae enter the soil and form the pupal stage. Adult moths emerge from pupae. Moths mate and lay eggs, thus starting the life cycle over again.

Several generations (a generation is the development from egg to adult stage) occur each year and typically take about 28 days to complete. Generation time can be extended if cooler temperatures occur and can last up to several months. Armyworms in the spring and summer occur in more distinct groups than later in the season. Fall populations of larvae often blend together several generations and may appear to be continually occurring. Some detail on the species mentioned follow.

Fall Armyworm – The fall armyworm overwinters in the pupal stage in the southern regions of Texas. The adult is a moth that migrates northward as temperatures increase in the spring. The adult moth has a wingspan of 32-40 mm (about 1.5 in.). The hind wings are silver-white; the front wings are dark gray, mottled with lighter and darker splotches. Each front wing has a noticeable whitish spot near the extreme tip on the males. Larval color can vary from light tan to shades of green. The head is brown or black with a prominent white line between the eyes which forms an inverted “Y.” The fall armyworm has four large spots on the upper surface of the last segment of its body. Along the middle of the larva’s back is a wide, yellowish-gray band with a dark, black stripe just below the yellowish-gray band.

Yellowstriped Armyworm – The yellowstriped armyworm moth has dark forewings with white and brown markings, and white hind wings. The wingspan ranges from 32 to 38 mm. The larva has a brownish head and bright yellow stripes near the top of the sides of the body and a pair of black, triangular spots running the length of the body.

Beet Armyworm – Adult beet armyworm moths have wingspans of 25 to 32 mm, with forewings that are mottled gray or brown with a pale spot near the center of each wing. The hind wings are a uniform gray or white. The larva is usually green but color can vary, with dark lateral bands running the length of the body. The larva has a single, dark spot behind the head and directly above the second pair of true legs (located directly behind the head). Beet armyworms tend to be more of a problem in hot, dry conditions and are usually a significant pest in vegetables and other broadleaf plants (such as cotton).

Armyworm – The adult moths are grayish tan, with small salmon or orange-pink dots on the forewings. The armyworm larva has a dark band running lengthwise along the middle of the back with a pale stripe just below the dark band. Fall armyworm has the reverse coloration. Armyworm caterpillars have a net-like or “honeycomb” pattern in their eyes and a dark band at the top of each proleg (unjointed legs near the back of the body). Armyworm larvae lack the inverted “Y” and four black spots on the last segment which are characteristic of the fall armyworm.

PEST STATUS AND CONTROL

When feeding, larvae strip foliage and then move to the next available food. High populations appear to march side by side to the new food. Thus, the name armyworms is derived.

Armyworms attack many different kinds of plants. When food is scarce, they will move to plants that are not normally attacked. Thus, armyworms can be found on nearly any plant as they migrate in search of edible foliage. Plants attacked by armyworms include: bermudagrass, fescue, grain and forage sorghum, corn, small grains, sweet potato, beans, turnip, clover, spinach, cucumber, potatoes, tomatoes, cotton and cabbage.

Damage consists of defoliation. The small larvae will chew the green layer from the leaves, creating a “window pane” effect. The first three instars cause very little feeding damage while the last two instars consume 85% of the total foliage consumed.

Control-Although armyworm outbreaks are memorable when they occur, in reality, the outbreaks are usually small in scope. Weather and natural enemies usually act together to keep populations under control.

Parasites such as wasps and flies are very effective against armyworms. Predators, such as ground beetles, are also effective in limiting outbreaks. Birds, skunks and rodents also consume large numbers of larvae and pupae. Diseases such as insect viruses and fungi can also be important.

However, conditions can occur that favor armyworms. High egg survival of fall armyworms is favored by above average rains in August and September. Beet armyworm outbreaks are likely in hot, dry conditions or when multiple applications of insecticides reduce natural enemies. Because armyworm moths are strong fliers, outbreaks can also occur when storms move the moths and allow them to escape natural enemies.

Armyworms should be controlled when they occur in large numbers or plant damage is becoming excessive.
The fall armyworm outbreaks usually occur late in the summer and early fall. Preventive treatments normally are not justified because attacks are sporadic and egg mortality is usually high. A variety of natural enemies keep fall armyworm larvae down to moderate numbers. Early detection of larvae is the best management tool and is achieved by frequent, thorough inspection of plants. Outbreaks seem to occur shortly after a rain or supplemental irrigation.

Fall armyworms feed any time of the day or night, but are most active early in the morning or late in the evening. Susceptible fields or lawns should be scouted by counting the number of armyworms in a square foot area in 8 different sites. Divide the total worm count by 8 to find the average number of armyworms per square foot. Be sure to take samples in the interior of the field because this pest is often heaviest near the field margins. Sometimes, only the field margins require treatment.

The threshold level ranges from two to three larvae per square foot for seedling wheat. For older plants, three to four larvae and obvious foliage loss justify control measures. Thresholds in improved pastures and lawns vary with conditions but treatment should be considered when counts average three or more worms per square foot.

Insecticide choices vary with the crop but the following (with product names and grazing restrictions in parentheses) are labeled for use in pastures include carbaryl (Sevin®) (14 days), malathion (0 days), methomyl (Lannate®) (7 days), methyl parathion (Penncap®-M) (15 days) and various biologicals such as Dipel®(0 days). Insecticide labeled in lawns and turf include halofenozide (Mach® 2), bifenthrin (Talstar®), cyfluthrin (Tempo®, Bayer Advanced®), carbaryl (Sevin®) permethrin (multiple brands) and spinosad (Conserve® and others).

FOR MORE INFORMATION

For more information about armyworms refer to Extension publications B-1220, Managing Insect and Mite Pests of Texas Sorghum; B-1251, Managing Insect and Mite Pests of Small Grains; B-1401, Integrated Pest Management Guide for Texas Forage Crops; and E-5, 6 and 7 Managing Insect and Mite Pests of Cotton.

ACKNOWLEDGMENTS

The authors wish to thank Drs. Allen Knutson, Mike Merchant, Mark Muegge and Carl Patrick for their assistance in reviewing this publication.

Silverfish and Firebrats

September 27, 2017 by

Wizzie Brown* and John A. Jackman**
* Extension Agent – IPM
** Professor and Extension Entomologist, The Texas A&M University System

Silverfish and firebrats belong to the insect order Thysanura. These insects differ from most other insects by continuing to molt, or shed their exoskeleton, throughout their entire lives.

Silverfish and firebrats are usually considered a nuisance when they invade homes. They consume and stain books, fabric, foods and wallpaper. These insects prefer starchy foods such as flour, rolled oats, paper or glue. Damage is only significant if a large population is present for a long period of time.

Biology and Description

Silverfish and firebrats have flattened elongate bodies that taper at the end like a carrot. They have chewing mouthparts, long antennae, no wings and three tail-like projections at the end of the abdomen. Fine scales cover their bodies. Silverfish and firebrat immatures look like the adults, only smaller in size.

Silverfish and firebrats typically run quickly and are mostly active at night. In homes, they are commonly found in closets, attics or near bookcases and hide behind baseboards or casings around doors and windows.

The silverfish (Figure 1), Lespisma saccharina (Linnaeus), is probably the most important pest species of Thysanura. Silverfish like temperatures between 70-80 o F with a relative humidity of 75-95%. Females lay eggs singly or in batches either daily or at irregular intervals depending on food availability. Eggs hatch in about 40 days with low temperatures (about 70 o F) or 20 days with high temperatures (about 90 o F). Silverfish may molt up to 60 times in their lifetime, which is usually about 2-3 years.

Figure 1. Silverfish, Lespisma saccharina (Linnaeus).

The firebrat, Thermobia domestica (Packard), is similar to silverfish, but is mottled brown. Firebrats prefer temperatures over 90 o F and therefore are often found near ovens, dryers or hot water heaters. Eggs are laid in batches with an average of 50 per batch. Under good conditions, the eggs hatch within 13 days and the nymphs begin to their development. Firebrats may molt 50 to 60 times during its lifespan which can be up to 2 years in warm areas.

Control

Sanitation should be used to avoid infestations of silverfish and firebrats. It cannot be used as the only means to eliminate infestations. Remove old books, magazines and newspapers. Inspect fabrics that have been stored for long periods for damage or infestation. If books or fabrics will be in storage, store these items in sealed plastic containers. Many times valuable books or papers have infestations of silverfish. These items can be placed into a sealable plastic bag and placed into the freezer for several days to kill the silverfish.

Clean closets on a regular basis to help remove harborage areas. Vacuum regularly and clean up spilled food or drink immediately. Make sure to inspect any items brought into the home, especially those that have been in storage, to avoid an infestation.

In areas of infestation, or areas where books are stored, reduce humidity by using air conditioning units, fans or dehumidifiers. Repairing any plumbing leaks will cut off water sources for these insects.

Insecticide treatments should be targeted to harborage areas such as cracks and crevices, around baseboards, closets and attics. With large infestations, small holes may be drilled in walls to treat the wall void.

Look for products labeled to control silverfish, firebrats or bristletails. Natural active ingredients include d-limonene, clove oil, thyme oil, boric acid or diatomaceous earth. Synthetic active ingredients are items such as bifenthrin, lambda-cyhalothrin, cypermethrin, permethrin or deltamethrin.

Formulations of the above mentioned products may be baits, dusts, or aerosols. These formulations should be used in crack and crevice treatments, in attics, wall voids and other areas inaccessible to children and pets. Dusts should be used with care, and should not be inhaled as they are being applied.

It is advisable to use the services of a pest control operator when the infestations are large, persistent or hard to find. A commercial operator has the knowledge, training and equipment to perform safe and effective control.

Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide USER is responsible for the effects of pesticide residues on plants or household goods, as well as problems that could arise from contamination of neighboring properties or plants. Always read and follow carefully the instructions on the container label.

Acknowledgements

The authors wish to thank Kim Engler and Alan Brown for review of this manuscript.

Photograph by Bastiaan “Bart” M. Drees.

Managing Insect and Mite Pests in Vegetable Gardens

February 2, 2008 by

Structure-Infesting Wood-Boring Beetles

October 17, 2005 by

John A. Jackman*
*Professor and Extension Entomologist, The Texas A&M University System

Several kinds of beetles damage stored wood, structural timbers and other wood products. The tunneling activities of the larvae and the emergence of adults can weaken wood and may destroy its appearance.

Wood-boring beetles come from at least 12 insect families and vary greatly in size, wood preference, nature of damage and other habits. Although preventing beetle infestations is desirable, control measures are available if infestations are found. To control wood-boring beetles, it is extremely important that the beetles or beetle damage be identified properly, as control measures vary by species.

Other insects also attack and damage wood, including termites, carpenter ants and carpenter bees. Their appearance and damage characteristics vary greatly.

Detection

Powderpost beetle tunneling.

There are several indicators that wood-boring beetles are present. Probably the most common sign of a wood-boring beetle infestation is the presence of holes chewed by the adult beetles upon emergence. Another indicator is a powdery material called frass that beetles often produce while feeding. Frass is plant fragments made by a wood-boring insect; it is usually mixed with excrement. The beetles push the frass from the holes they have made in the infested wood. This frass usually gets piled below the holes or in cracks in structures. The consistency of the frass ranges from very fine to coarse, depending on the species.

Sometimes an infestation is indicated by the presence of wood-boring beetle adults. Adult beetles that emerge in confined structures are attracted to lights or windows and may accumulate at these locations.

Other signs of an infestation include stained wood or a blistering appearance on the wood surface caused by larvae tunneling just below the surface. Less commonly, immature beetles produce audible rasping or ticking sounds while chewing on the wood. These chewing sounds are most often heard during quiet times at night.

Identification

If you discover beetle adults, beetle larvae or other evidence of an infestation, obtain a correct identification of the beetle family or species involved. Identification is important to make informed decisions about whether the beetles are likely to continue to attack the wood in your home and whether treatment is justified. Adult wood-boring beetles range from under 1⁄8 inch to more than 2 inches long. Although many are dark colored, some are metallic blues, metallic greens or striped with yellow or red. If you find only adults, try to find any emergence holes or damaged wood, which identifies the area infested. Immature wood-boring beetles usually remain inside the wood and therefore are seldom seen. These grubs are typically soft and fleshy, white to cream-colored with a distinct head capsule that is brownish. The size varies from very tiny just after hatching to more than 2 inches long. The bodies are noticeably segmented and elongate. They may be cylindrical or flattened. Knowing the kind of wood—hardwood or softwood—can help you identify the beetle species involved. Sometimes wood-boring beetles enter homes accidentally because they are attracted by lights; in these cases, they almost never damage property. More often, beetle infestations arise from the use of infested wood during the construction of the house.

Typical wood-boring beetle life cycle

Biology and habits

Wood-boring beetles have four life stages: egg, larva, pupa and adult. The eggs and pupae do not feed. Larvae, or grubs, are the main damaging stage, but the adults of some species can also damage wood.

Most types of wood-boring beetles do not damage seasoned structural timbers or finished wood products. However, if infested wood is used in construction, beetles can emerge from structural timber, doors, flooring, molding or paneling.

The length of the life cycle (egg to adult stage) of wood-boring beetles varies greatly among species and under different environmental conditions. Some beetles complete a life cycle within a few months; others have been known to live in wood as larvae for up to 30 years before emerging as adults. This complicates detection and control because it is difficult to assess the length of time an infestation has been present. The variation in biology for these beetles is outlined in Table 1.

The emergence holes of wood-boring beetles are usually round, but some species produce semicircular or oval holes. The shape and size of the emergence holes can help identify beetle groups.

The type and location of frass is also characteristic of various beetle groups. Notice whether it is packed into the tunnels or extruded through exit holes. Also, note its texture (powdery, pelletized, coarse or shredded). All these characteristics can help identify beetles when no specimen is available. A hand lens is often helpful to determine the frass characteristics of wood-infesting beetles.


Powderpost larva (3-5 mm)	Typical length of powderpost beetle adult (4-6 mm)

Often, various beetle groups can be recognized and control measures planned based on knowledge of their wood preferences. Table 2 summarizes the types of wood attacked, the usual damage or emergence sites in buildings and reinfestation capabilities. This table should help in planning appropriate control measures.

For instance, the lyctid powderpost beetles attack only seasoned hardwoods, and they are serious pests when they do. Thus, lyctid powderpost beetles found in hardwood floors, wood trim, or furniture would not be expected to attack softwood such as pine timbers in a home. On the other hand, deathwatch beetles attack both softwoods and hardwoods, and they generally feed on seasoned wood.

Table 1. Biological characteristics of wood destroying beetles.

	Exit hole
Group	Diameter	Shape	Destructive Stage	Typical length of life cycle	Type of frass
Lyctidae (Powderpost beetles)	1⁄32 to 1⁄16 inch	Round	Larva	3 months to 1 year	Flour or talc-like; readily pours out of exit holes and cracks
Anobidae (Deathwatch beetles)	1⁄16 to 1⁄8 inch	Round	Larva	1 to 3 years	Fine to coarse; pellet shapes; usually a gritty quality; loose in tunnels; little at exit holes
Bostrichidae (False powderpost beetles)	1⁄8 to 3⁄8 inch	Round	Larva and adult	Usually 1 year	Fine to coarse; tightly packed; tends to stick together
Ptinidae (Spider beetles)	1⁄16 to 1⁄12 inch	Round	Larva	Several months under favorable conditions	Fine and powdery; fills larval tunnels
Curculionidae (Weevils, snout beetles)	1⁄32 to 1⁄16 inch	Round	Larva and adult	Varies with species	Powdery or granular dusts packed in irregular tunnels
Buprestidae (Flatheaded borers)	1⁄32 to 1⁄2 inch	Oval	Larva	1 to 30 years	None at exit holes; coarse powder in tunnels
Oedemeridae (Wharf borer)	1⁄4 inch	Round	Larva	About 1 year	Shredded and moist
Cerambycidae (Roundheaded borers)
1. Old house borer	1⁄4 inch	Oval	Larva	1 to 32 years (normally 3 to 10)	Tunnels filled with powdery dust often formed in pellets
2. Flat oak borer	1⁄16 to 1⁄12 inch	Slightly oval	Larva	1 to several years	Tunnels packed with fine flourlike dust and granules
3. Other roundheaded borers	1⁄8 to 1⁄2 inch	Round	Larva	Variable	Coarse and fibery in tunnels
Scolytidae (Bark beetles)	Less than 1⁄16 inch	Round	Adult and larva	2 months to 1 year or more	Little or none at exit holes; very little or none in tunnels
Brentidae, Lymexylidae, and Tenebrionidae (Timber worms)	Less than 1⁄32 to 1⁄8 inch	Round	Larva	Unknown; probably several years	Galleries free of frass and not stained

Old house borer larva

Typical length of old house borer adults (12-18 mm)

One of the most significant wood infesting beetles is the old house borer, which is a member of the roundheaded wood borer family. It generally attacks structural softwoods. Contrary to its name, it is often a pest in newer homes built with infested wood. Wood becomes susceptible to attack if it is improperly kiln-dried or treated, or stored too long. This insect will readily reinfest structural timbers.

Because other beetle groups do not reinfest structural timbers, controlling them may be unnecessary. Most flatheaded borers, roundheaded wood borers and bark beetles are found shortly after a structure is built. Adults of these species generally will emerge within a few years after a building has been constructed. These beetles do not normally reinfest seasoned structural wood.

Prevention

Prevention is the best way to avoid damage caused by wood-boring beetles. Several standard procedures are available to eliminate or avoid these problems. Some management efforts start when the wood is harvested. Timber should have the bark removed soon after it is felled, to inhibit egg laying of wood-boring beetles. Lumber should be removed from the forest as quickly as possible and allowed to dry. Kiln drying of lumber will kill beetles infesting the wood. However, because kiln drying has no lasting effects, reinfestation is possible in some situations.

Table of Attack Sites of Wood-Destroying Beetles

Powderpost beetle damage.

Before buying wood, evaluate it closely by inspecting it for exit holes or other signs of infestation. Buy and use only structural wood and wood trim that has been properly kiln-dried or chemically treated. Proper kiln-drying will eliminate any infestation. However, infestations may still occur in wood that is stored after being kiln-dried. Wood that is treated chemically in pressure chambers will resist infestation for many years.

Control moisture in the home or structure. Moisture-control options include repairing leaks and installing vapor barriers, insulation, dehumidifiers and air conditioners. Most wood-infesting beetles cannot develop in wood that has a moisture content of less than 15 percent. Low moisture will also help prevent decay, which can aggravate wood-boring beetle problems.

Maintain a fresh coat of paint or varnish on all furniture or exposed wood in your home. Most wood-boring beetle species will not reinfest wood that is painted, varnished, waxed or covered with some other type of finished surface. Avoid introducing new sources of wood-boring beetles, such as firewood. Adult beetles and various other pests can emerge from wood temporarily stored in the home and then infest structural wood or furniture or become a nuisance.

Store firewood as far from the home as possible or at least stack it away from the outer walls. Bring in only the wood that will be used immediately.

Before buying, carefully inspect antique furniture, picture frames, bamboo products and other wood items. Consider the wood to be actively infested if you see any evidence of recent emergence holes, larval infestations or frass. Treat these items properly before placing them in your home or in storage.

Control

Several options are available for controlling wood-boring beetles. First, try to identify the specific beetle or beetle group involved. Once recognized, determine the extent of the damage and evaluate the structural characteristics of the infested building. This information will help you determine a proper plan for any control efforts.

The most common methods used to control wood-infesting beetles include replacement of infested wood, temperature treatment of the wood, surface treatment with insecticides, or fumigation. If the infestation is localized, replacing infested wood is often a good choice. Remove or replace structural wood or furniture whenever it is economically feasible. Replacement reduces the risk of spread or reinfestation and eliminates any unsightly damage visible in the finished structure.

It is difficult to treat an entire structure for wood-boring beetles with heat or cold. However, it is feasible to treat small home furnishings, wooden artifacts or furniture by freezing or heating them to eliminate wood-boring beetles. To freeze wood-boring beetle larvae, maintain the wooden items at about 0 degrees F for several weeks to eliminate an infestation, because many wood-boring beetles are resistant to cold temperatures.

Alternately, heat can kill insects in wood by maintaining the wood at temperatures of 140 to 150 degrees F for 2 to 4 hours. However, wood thicker than 2 inches may take a long time to heat internally, so expect to hold the wood much longer at appropriate temperatures. Be aware that surface temperatures of wood seldom reflect the internal temperature. Extremely high temperatures probably help reduce beetle infestations in many attics.

Pesticide treatments for wood-boring beetles are best done by a licensed pest control operator. A localized infestation may be treated by spraying or brushing a residual insecticide on the wood surface.

Depending on the product used, the insecticide may stay near the surface or penetrate deeper. Insecticides that stay near the surface affect only the adults that emerge from the wood or attempts to reinfest the wood. Larval development beneath the wood surface often continues. Surface treatments that do not penetrate generally do not control infestations of wood-boring beetles that bore deeply into the wood. Some of those, such as the old house borer, have adults that can mate and produce eggs without leaving their larval tunnels.

Products containing beta-cyfluthrin (Bayer® Power Force Carpenter Ant & Termite Killer Plus), bifenthrin (Ortho® Termite & Carpenter Ant Killer), and cyfluthrin (Bayer® Advanced® Home, Home Pest Control Indoor & Outdoor Insect Killer) are registered for homeowners to use to control wood-boring beetles. Several other products containing those active ingredients, or others such as cypermethrin, deltamethrin, fenvalerate, imidacloprid and lambda-cyhalothrin, are available to pest control operators. Because surface treatments with these products do not penetrate the wood very well, they are used primarily to prevent the next generation of wood-boring beetles from establishing in the wood.

Wood penetrating treatments are possible with water-soluble borate products such as Tim-Bor® and Bora-Care®. These products are best used on freshly installed wood before completion of home construction. Applications are typically made as a water emulsion applied twice, the second time before the first application dries completely. Applications to unfinished wood surfaces will allow some penetration into the wood.

However, many types of wood finishes— paint, varnish, wax—do not permit insecticide penetration. Also, outdoor structures or wood surfaces that are exposed to moisture are poor candidates for treatment with borates because of leaching. Water exposure tends to draw out soluble compounds, rendering the treatments less effective over time.

The most reliable and effective method of eliminating wood-boring beetles is fumigation. Fumigation involves introducing a toxic gas into a structure, usually under a gas-proof tarp. The fumigant gas penetrates beneath the wood’s surface to kill all life stages of the beetle.

Fumigation does not prevent subsequent reinfestation. Because it is a costly, highly technical and hazardous process, fumigation must be done by a licensed pest control operators experienced with this technique.
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Insecticide label clearances are subject to change and changes may have occurred since this publication was printed. The pesticide user is always responsible for the effects of pesticides on his own plants or household goods as well as problems caused by drift from his property to other property or plants. Always read and follow carefully the instructions on the container label.

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A previous version of this publication was written by J. A. Jackman and P. J. Hamman.

The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas AgriLife Extension Service is implied.