Wood-boring in Homes

Integrated Management in the Home

Three groups of wood-boring - IDENTIFICATION AND LIFE tles—powderpost, deathwatch, and CYCLES false powderpost (Table 1)—invade Powderpost Beetles and damage wood furniture as well as structural and decorative wood A subfamily of beetles in the family inside of buildings. The larvae (formerly referred to as the family Lyctidae) are known as pow- feed in and do most of the damage derpost beetles (Fig. 1), because larvae to wood, and when they reach the create a fine, dustlike powdered frass (a adult stage, they emerge through mixture of feces and wood fragments) round exit holes, which they create by that has the consistency of baking flour chewing through the wood surface. or talcum powder. This boring dust is Figure 1. Adult , Lyc- Adults of some also bore exit packed into the larval galleries (feeding tus planicollis. holes through plaster, plastic, and channels) in the wood but occasionally even soft metals that might cover the falls out of exit holes into small piles on underlying wood. floors or other surfaces.

You might see other wood-boring bee- This fine, powdery frass distinguishes tles such as flatheaded or roundheaded powderpost beetles from other wood- borers and bark or ambrosia beetles boring beetles in homes (Fig. 2). It also in your home if you store infested differs from the larger, granular, and firewood inside. However, these typi- almost pepperlike pellets drywood ter- cally are forest that won’t attack mites leave behind; if you look closely wood structures or furniture. They at termite pellets, you will see they begin their life cycles on declining have ridges on their sides. Figure 2. Powderpost beetles produce much finer boring dust (left) than other trees that are old or that have sustained wood borers such as deathwatch beetles fire or damage. Sometimes these Powderpost beetles attack hardwoods, in the family Anobiidae (right). forest insects are present in trees when apparently because these woods have they are milled into wood products, pores into which they can lay eggs; and they might cause alarm when they softwoods don’t have such pores. The with high starch content; the starch emerge from infested wood used in large pores in bamboo also make it a content in softwoods is nutritionally low for these beetles. They will attack newly constructed buildings. However, favored host material for powderpost beetles. In addition to large pore size, wood that is very dry and that has a they aren’t able to reinfest the wood in powderpost beetles also prefer wood moisture content as low as 8%. these structures. Table 1. Certain species of wood wasps also Frequently Encountered California Species of Powderpost, Deathwatch, and False might emerge from infested wood used Powderpost Beetles.1 in new structures. See Pest Notes: Wood Group name Common name Latin name Wasps and Horntails for more informa- tion. Invasive wood-boring insects powderpost old world beetle (Stephens) (Lyctinae)2 southern lyctus beetle Lyctus planicollis LeConte often arrive as hitchhikers from other western lyctus beetle LeConte continents on solid wood packing deathwatch Pacific gibbicollis (LeConte) material such as pallets or in a ship’s (Anobiidae) dunnage, and some of the key beetle false powderpost black Polycaon stoutii (LeConte) pests of wood in structures have likely (Bostrichidae) leadcable borer declivis (LeConte) established worldwide distributions 1 Based on a survey conducted in March 2010 of some of the principal insect collections in California—Bohart this way. Museum, California State Collection of , and Essig Museum. 2 Recently a taxonomic change has been recommended to incorporate the former family Lyctidae as a subfamily Lyctinae within Bostrichidae. However, the biology and field visual signs of damage for the subfamily Lyctinae remain unchanged.

EST OTES Publication 7418 PUniversity of California N Statewide Integrated Pest Management Program Agriculture and Natural Resources June 2010 June 2010 Wood-boring Beetles in Homes

Adult powderpost beetles most often dation timbers, and some types of fur- select and lay eggs in wood such as , niture. You’ll typically find this beetle ash, hickory, mahogany, and walnut, in old wood or wood that is partially and infestations are most likely to oc- decayed. Deathwatch beetles prefer cur in wood paneling, molding, floor- wood that is more moist—greater than ing, window and door frames, plywood, 14% moisture content—than what pow- bamboo articles, and furniture. Infesta- derpost beetles prefer, so they might be tions can occur if beetles or larvae are less of a problem in houses with central brought into a building in furniture, heating and air conditioning; you are firewood, or wooden decorative articles. more likely to encounter them in damp sub areas, basements, or outbuildings. Figure 3. Powderpost beetles leave tiny, Sometimes the only sign of infesta- Unlike powderpost beetles, deathwatch round exit holes in wood after they tion is the tiny, round exit holes made beetles in California are more likely to emerge as adults. by the emerging adult beetles (Fig. 3). invade structures from wild popula- Once they emerge, the winged adults tion sources located outdoors. spread to other wood surfaces where they deposit eggs onto unfinished Deathwatch beetle larvae fill their gal- surfaces or in cracks or other open- leries with very small pellets of frass ings. They also tend to fly toward light, (smaller than the pellets drywood ter- so you’ll typically find dead adults on mites produce), which gives their frass windowsills after they have tried to a slightly grittier consistency than that disperse. of powderpost beetles but not as coarse as that of false powerpost beetles. How- They have a life cycle ranging from 3 ever, like powderpost beetles, the lar- Figure 4. Adult deathwatch beetle. months to more than 1 year, depend- vae (Fig. 5) do most of the damage, and ing on temperature, humidity, and the their frass is packed in the galleries and nutritional quality of the wood. Adult is visible only when larvae or adults powderpost beetles usually are shades push it out through emergence holes. of brown to red. Species frequently Holes that deathwatch beetles leave encountered in California structures can be of various sizes, whereas those include the old world lyctus beetle, Lyc- from powderpost or false powderpost tus brunneus; the southern lyctus beetle, beetles tend to all be the same size. Lyctus planicollis; and the western lyctus beetle, Lyctus cavicollis. Adults are reddish to dark brown and lay eggs in crevices, small openings, or Deathwatch Beetles pores of unfinished wood. It can take 2 Figure 5. Deathwatch beetle . Wood-boring beetles in the family years to complete each generation. The Anobiidae are known as deathwatch species frequently encountered in Cali- beetles (Fig. 4). They are closely related fornia is the Pacific deathwatch beetle, to the drugstore and cigarette beetles, . which are stored-products pests. Adults communicate with each other False Powderpost Beetles and probably locate mates by tapping Wood-boring beetles in the family their heads against wood, usually at Bostrichidae are sometimes known as night. Deathwatch beetles might have false powderpost beetles. False pow- acquired their name during medieval derpost beetles colonize a variety of times in Europe when people heard the hardwoods and sometimes softwoods. Figure 6. Frass-packed galleries made tapping while sitting up with a sick or Tropical species of Bostrichidae fre- by leadcable borer, a false powderpost dying person during the night. Legend quently are imported into the United beetle, in redwood. This frass is much has it they attributed the sound to the States on bamboo articles or on woods coarser than that produced by powder- tapping of the staff of the scythe of the such as Philippine mahogany or lauan. post or deathwatch beetles. grim reaper coming to take away the soon-to-be deceased. Unlike female powderpost and death- terials then deposit their eggs in pores watch beetles, which lay their eggs or cracks within the tunnel. Larvae of Deathwatch beetles primarily infest while on the wood surface, false pow- false powderpost beetles pack their gal- softwoods, especially Douglas-fir, derpost beetle females bore a tunnel, leries very tightly with frass that has which is used in girders, beams, foun- or egg gallery, into wood or other ma- the consistency of coarse powder simi-

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lar to powdered borax soap (Fig. 6). The MANAGEMENT texture of this frass is the most gritty The first step in managing wood- of the three groups and distinguishes boring beetles is identifying the group false powderpost beetles from true involved in the problem. Two quick powderpost beetles and deathwatch diagnostic tests, the ballpoint pen test beetles. and the frass test (Table 2), can help distinguish among the three groups In buildings, false powderpost beetles of wood-boring beetles. Detection can infest floors, furniture, hardwood be difficult, because much of their life paneling, and other wood materials. cycle takes place beneath the wood Adults of some species bore through Figure 7. Head and thorax of a lead- surface and in hidden wood junctions cable borer showing the humpback soft metal such as lead and silver as where a homeowner or inspector might appearance typical of false powderpost well as plaster and other nonwood not easily detect them. beetles and deathwatch beetles. materials, searching for sites to deposit eggs or protection from weather ex- Wood-boring beetles are difficult to tremes. This gives rise to the common control once an infestation has begun. types of pests is an important phytos- name “leadcable borer” for one species, Therefore, prevention is the best man- anitary regulation adopted by current , because of its habit of agement method. Protective measures international convention. boring into the metal covering of sus- should take place at every stage of lum- pended telephone or electrical cables. ber processing and handling including Thoroughly inspect materials used for lumber mills, plywood mills, lumber- constructing buildings before use to This species also is known for its habit yards, furniture-manufacturing facto- ensure they don’t contain wood-boring of attacking wine-soaked oak in wine ries, and building-construction firms. beetles. Protect wood from infestation barrels or the corks in alcohol specimen by painting or varnishing to seal pores, vials in insect collections; hence it also Sanitation is the most important aspect cracks, and holes where these beetles has been called the “cask borer.” In the of prevention. Remove and destroy could lay eggs. To keep from acciden- wild in California, the leadcable borer dead tree limbs around buildings or tally introducing wood-boring beetles frequently is associated with dying near any area where wood products into a finished structure, inspect furni- branches on native oak and walnut are stored. Destroy scrap lumber and ture and other objects before bringing trees. In urban and rural outdoor set- other wood products before infestation them into buildings. Remove and fu- tings, it can be found in association occurs. migate objects that show signs of beetle with eucalyptus and other ornamental infestation. hardwood trees. For some pests such as the black Poly- caon false powderpost beetle, curtail- When bringing in firewood, limit your- Adult false powderpost beetles are dark ment of exterior mercury vapor lighting self to only what you will burn that brown or black, sometimes with red- around lumberyards and warehouses day. Also, inspect buildings for signs dish mouthparts, legs, and antennae. of wood-boring beetle damage. Look 1 is recommended to reduce the chances Adults of most species are about /4 inch of attracting the beetle to the site. Kiln for exit holes where adult beetles have long, but one very abundant native drying lumber destroys beetle infesta- emerged, and be aware of any new California species, the black Polycaon, tions, although it doesn’t prevent re- beetles accumulating on your window- 1 Polycaon stoutii, is 1 /2 to 2 inches long. infestation. Heat treatment of the core sills. Once you have located galleries, Adult false powderpost beetles have a of imported wood packing material to tap out the frass to aid in identifying humpback appearance, so you typically 133°F for 30 minutes to combat these the pest (Table 2). won’t see the head if you view the bee- tle from above (Fig. 7). This characteris- Table 2. tic also is true of deathwatch beetles. Two Methods for Distinguishing Powderpost, Deathwatch, and False Powderpost Beetles. The duration of the false powderpost 1 2 beetle life cycle varies. Most species Group name Ballpoint pen test Frass test develop in 1 year, but the black Poly- powderpost Only the tip of the pen fits into Feels like talcum powder. caon can take up to 20 years to develop. (Lyctinae) the exit hole. In California, this species frequently deathwatch The tip and part of the angled Feels gritty. is encountered in hardwood flooring (Anobiidae) face fit into the exit hole. from oak, ash, walnut, cherry, or even false powderpost The entire point of the pen It is difficult to dislodge the madrone and is thought to infest the (Bostrichidae) usually fits into the exit hole. frass from the hole. raw flooring material at the mill or 1 Insert the tip of a click-type, refillable ballpoint pen into the exit hole of the beetle. holding areas prior to construction. 2 To determine the texture of frass, a mixture of feces and food fragments, rub it between your fingers.

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You can heat small wooden items—but Suomi, D. A., and Akre, R. D. 1992. Thoms, E. M., and R. H. Scheffrahn. not those containing fabrics, pelts, or Characteristics of structures attacked 1994. Control of pests by fumigation paints—in an oven at 120° to 140°F for by the wood-infesting beetle Hemicoe- with Vikane gas fumigant (sulfuryl 6 hours. You also can place items in a lus gibbicollis (Coleoptera: Anobiidae). J. fluoride). Down to Earth 49(2):23–30. deep freezer at 0°F for 72 hours. Longer Entomol. Soc. Brit. Columbia 89:63–70. treatments might be necessary if the Williams, L. H., and Sprenkel, R. J. 1990. wood is thicker than 2 inches. Suomi, D. A., and Akre, R. D. 1992. Ovicidal activity of sulfuryl fluoride to Control of the structure-infesting bee- anobiid and lyctid beetle eggs of vari- Remove and replace infested structural Hemiocoelus gibbicollis tle (Coleoptera: ous ages. J. Entomol. Sci. 25:366–375. v wood whenever possible to eliminate Anobiidae) with borates. J. Econ. Ento- beetles. Destroy infested wood by mol. 85:1188–1193. burning or take it to a landfill. Where removal isn’t possible, liquid insecti- cides can be applied to bare structural wood. The most effective and safest materials are formulations AUTHORS: V. R. Lewis, Environmental University of California scientists and other containing sodium borate (e.g., Tim- Science, Policy, and Management, UC qualified professionals have anonymously peer reviewed this publication for technical accuracy. The Bor and Bora-Care), which a licensed Berkeley; and S. J. Seybold, USDA Forest ANR Associate Editor for Urban Pest Management operator must apply. These Service, Pacific Southwest Research Station, managed this review process. materials must penetrate wood to kill Davis, Calif. To simplify information, trade names of products have been used. No endorsement of named products beetle larvae that are within, so fin- TECHNICAL EDITOR: M. L. Flint is intended, nor is criticism implied of similar products ished wood can’t be successfully treat- that are not mentioned. This material is partially based upon work ed. Depth of penetration is enhanced EDITOR: M. L. Fayard supported by the Extension Service, U.S. Department in moist wood; if moisture is less than of Agriculture, under special project Section 3(d), 15%, penetration might occur only in ILLUSTRATIONS: Fig. 1, J. Gross; Figs. Integrated Pest Management. 2-3, R. L. Tabuchi; Figs. 4-5, D. A. Suomi; the top 1 4 inch. / and Figs. 6-7, J. K. Clark. Produced by UC Statewide Integrated Pest Management Program For extensive powderpost and death- University of California, Davis, CA 95616 watch beetle infestations within a This and other Pest Notes are available at building or where inaccessible struc- www.ipm.ucdavis.edu. tural parts of a building are involved, For more information, contact the University of many professional pest control opera- California Cooperative Extension office in your tors offer whole-building fumigation. county. See your telephone directory for addresses University of California Homeowners should bear in mind this and phone numbers, or visit http://ucanr.org/ce.cfm. Agriculture and Natural Resources Program method doesn’t prevent reinfestation; a new infestation could be initiated as WARNING ON THE USE OF CHEMICALS are poisonous. Always read and carefully follow all precautions and safety recommendations soon as the fumigant is removed from given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed, the structure. Research results have away from food or feeds, and out of the reach of children, unauthorized persons, pets, and livestock. Pesticides applied in your home and landscape can move and contaminate creeks, rivers, and oceans. demonstrated that fumigation works Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens best to control adults and larvae; wood- containing fruits or vegetables ready to be picked. boring beetle eggs require a higher Do not place containers containing pesticide in the trash or pour pesticides down the sink or toilet. Either use the pesticide according to the label, or take unwanted pesticides to a Household Hazardous Waste Collection dose of fumigant. site. Contact your county agricultural commissioner for additional information on safe container disposal and for the location of the Household Hazardous Waste Collection site nearest you. Dispose of empty containers by following label directions. Never reuse or burn the containers or dispose of them in such a manner that REFERENCES they may contaminate water supplies or natural waterways. Ivie, M. A. 2001. Bostrichidae. In R. H. Arnett Jr., M. C. Thomas, P. E. Skelley, NONDISCRIMINATION STATEMENT and J. H. Frank, eds. American Beetles, Vol. The University of California prohibits discrimination or harassment of any person on the basis of race, color, national origin, religion, sex, gender identity, pregnancy (including childbirth and medical conditions 2. Boca Raton: CRC Press. pp. 233–244. related to pregnancy or childbirth), physical or mental disability, medical condition (cancer-related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or service in the uniformed services (as defined by the Uniformed Services Employment and Reemployment Rights Act of O’Connor-Marer, P. 2006. Residential, 1994: service in the uniformed services includes membership, application for membership, performance of Industrial, and Institutional Pest Control. service, application for service, or obligation for service in the uniformed services) in any of its programs Oakland: Univ. Calif. Agric. Nat. Res. or activities. University policy also prohibits reprisal or retaliation against any person in any of its programs or activities Publ. 3334. for making a complaint of discrimination or sexual harassment or for using or participating in the investigation or resolution process of any such complaint. Suomi, D. A. 1991. Anobiid beetles in University policy is intended to be consistent with the provisions of applicable State and Federal laws. Inquiries regarding the University’s nondiscrimination policies may be directed to the Affirmative Action/ structures. Wash. State Univ. Ext. Bul. Equal Opportunity Director, University of California, Agriculture and Natural Resources, 1111 Franklin Street, No. 1577. 6th Floor, Oakland, CA 94607, (510) 987-0096.

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