Carpet Beetles

Integrated Pest Management in the Home

Carpet beetles, which belong to the their last larval skin if no other shelter family of beetles known as dermes- is available. Although larvae don’t tids, are pests in warehouses, homes, make webs as clothes moths do, their museums, and other locations where shed skins and fecal pellets, which are suitable food exists. In California, three about the size of a grain of salt, make it species of carpet beetles cause serious obvious where they have been feeding. damage to fabrics, carpets, furs, stored food, and preserved specimens—the Carpet beetle adults don’t feed on varied carpet beetle, the furniture car- fabrics but seek out pollen and nectar. pet beetle, and the black carpet beetle. They are attracted to sunlight, and you’ll often find them feeding on the Figure 1. Varied carpet beetle final-instar IDENTIFICATION AND flowers of crape myrtle, spiraea, buck- larval cast skin (left) and adults (center and right). LIFE CYCLE wheat, and other plants that produce All three carpet beetle species have abundant pollen. However, you can similar life cycles (Table 1). Adults accidentally bring these pests inside on its wing covers, or elytra (Figure 1). lay eggs on a larval food source such on items such as cut flowers. With their In older adults the scales that form this as woolen fabric or carpets or furs. rounded bodies and short antennae, pattern wear off, so the beetles appear Eggs hatch in about two weeks, and carpet beetles somewhat resemble lady solid brown or black. Outdoors, female the larvae feed for varying periods, beetles in shape. beetles search out spider webs or bee, depending upon the species and envi- wasp, or bird nests as places to lay their ronmental conditions; they prefer dark, Varied Carpet Beetle eggs. The nests and webs contain dead secluded places. When ready to pupate, The adult varied carpet beetle, An- insects, beeswax, pollen, feathers, or the larvae might burrow further into threnus verbasci, is about 1/10 inch long other debris that can serve as larval the food or wander and burrow else- and black with an irregular pattern of food. Indoors, beetles deposit eggs on where. They might also pupate within white, brown, and dark yellow scales or near wool carpets and rugs, woolen

Table 1. Life Cycle of Three Species of Carpet Beetles. Varied carpet beetle Furniture carpet beetle Black carpet beetle

actual size actual size actual size

adult larva adult larva adult larva 5. Blk carpet beelte adult, larva number of eggs laid 40 4. Varied carpet beetle larva 60 90 days before eggs hatch 10–20 9–16 6–16 days for the larval stage 220–630 70–94 166–330 days for pupation 10–13 14–17 8–14 weeks as an adult female 2–6; male 2–4 4–8 4–8

PEST NOTES Publication 7436

Statewide Integrated Pest Management Program November 2012 November 2012 Carpet Beetles

goods, animal skins, furs, stuffed ani- fornia and other arid areas, the black mals, leather book bindings, feathers, carpet beetle is a more serious stored- animal horns, whalebone, hair, silk, product pest than a fabric pest. dried plant products, and other materi- als that can serve as larval food. Adults DAMAGE usually appear in spring or early sum- Damage occurs during the larval stage mer; indoors, you’ll often find them of carpet beetles. Larvae feed in dark, near windows. undisturbed locations on a variety of dead animals and animal products Mature larvae are slightly longer than such as wool, silk, leather, fur, hair adults and are covered with dense brushes with natural bristles, pet hair, Figure 2. Furniture carpet beetle larva (left) and adults (center and right). tufts of hair they extend upright to and feathers; occasionally they feed on form a round plume if disturbed. They stored products such as certain spices have alternating light and dark brown and grains. They don’t feed on syn- stripes and are distinguishable from thetic fibers. other carpet beetle larvae because they are broader in the rear and narrower It’s not always possible to tell from in front. the damage whether clothes moths or carpet beetles caused it, but in general Furniture Carpet Beetle carpet beetles are more likely to dam- When viewed from above, adults of age a large area on one portion of a the furniture carpet beetle, A. flavi- garment or carpet while moth damage pes, (Figure 2) are slightly larger and more often appears as scattered holes. rounder than the varied carpet beetle. Also carpet beetle larvae leave brown, Figure 3. Black carpet beetle larva (left) and adult (right). Coloration and markings vary, but shelllike, bristly-looking cast skins the furniture carpet beetle generally when they molt. These skins and a lack has a mottled appearance due to the of webbing are usually good clues that where infestations are serious. Traps black spots that intersperse the white carpet beetles are the culprits. placed throughout a building can show and dark yellow to orange scales on its where beetles are coming from; the wing covers. If these scales have worn MANAGEMENT traps are also useful for monitoring the off, the adults can appear solid black. Carpet beetles are among the most dif- effectiveness of control practices. Check Their undersides are white. ficult indoor pests to control because traps once or twice a week. You can of their ability to find food in obscure also use pheromone traps to augment Larvae are white at first but darken places and to disperse widely through- other control methods if you use them to dark red or chestnut brown as they out a building. Successful control de- to attract adult males in small confined mature (Figure 2). In contrast to larvae pends on a combination of sanitation areas. Sticky traps are also available of the varied carpet beetle, these larvae and exclusion. If exclusion and sanita- without a pheromone; you can place are broader in front and narrower at tion are successful, insecticide treat- these traps on windowsills to trap the rear. Larvae of the furniture carpet ments aren’t required. adults that fly to windows. Plain sticky beetle feed on the same types of items traps are available in retail stores, while as varied carpet beetle larvae. Dermestids frequently fly into homes sticky traps baited with a pheromone from flowers in the landscape. A few are available from local pest control Black Carpet Beetle adult beetles in the house shouldn’t be operators, pesticide supply distributors, Adults and larvae of the black carpet cause for alarm. A management pro- and on the Internet. Pheromone traps beetle, Attagenus unicolor, (Figure 3) are gram needs to be implemented only if are species-specific, so it is important to distinctly different from the carpet you find larvae developing in fabrics in use one that attracts the species causing beetles described above. Adult black your home. your problems. carpet beetles range from 1/8 to 3/16 inch long. They are shiny black and When carpet beetles threaten products Eliminate the Source dark brown with brownish legs. Full- in commercial warehouses or storage Eliminate accumulations of lint, hair, sized larvae can be as long as 5/16 inch areas, a monitoring program using dead insects, and other debris that and range from light brown to almost sticky traps baited with an appropriate serve as food for carpet beetles. Throw black. Larvae are shiny, smooth, and pheromone (a chemical attractant an out badly infested items. Remove old hard, while short, stiff hairs cover their organism produces to attract others spider webs and bird, rodent, bee, and body. Their body tapers toward the rear of the same species) is recommended. wasp nests, which can harbor infesta- and ends in a tuft of long hairs. In Cali- Sticky traps can also be used in homes tions. Examine cut flowers for adult

◆ 2 of 4 ◆ November 2012 Carpet Beetles beetles before bringing the flowers Protecting Items in Storage Seal any holes or cracks, and if the lid inside. And be sure that window doesn’t fit tightly, seal it with tape, or To properly store items that are suscep- screens, doors, and vents are secure to wrap the entire container in heavy pa- tible to carpet beetles, first make sure keep carpet beetles from flying in from per and seal it with tape. the items are pest-free and clean, then outdoor sources. place them in an airtight container, in- Alternative methods for controlling serting a layer of paper every few inch- Regular and thorough cleaning of rugs, carpet beetles include heating the in- es. On these paper layers you can place draperies, upholstered furniture, clos- fested object in an oven for at least 30 insecticide-impregnated resin strips ets, and other locations where carpet minutes at 120°F or higher or enclosing that are labeled for control of carpet beetles congregate is an important pre- the object in a plastic bag and placing it beetles on fabrics, or you can use moth in a freezer for 2 weeks at temperatures ventive and control technique. Frequent, balls, flakes, or crystals, which contain below 18°F. Before using either of these thorough vacuuming is an effective paradichlorobenzene (PDB), also called methods, consider if cold or heat will way of removing food sources as well 1,4-dichlorobenzene. Don’t let these damage the object. as carpet beetle eggs, larvae, and adults. materials come in direct contact with After vacuuming infested areas, dis- plastic buttons, hangers, or garment The effectiveness of cedar chests and pose of the bag promptly, because it can bags, since the active ingredients can closet floors made of cedar is debatable. contain eggs, larvae, or adult insects. cause the plastic to soften and melt into Some cedar contains an oil that doesn’t the fabric. Also be sure to keep these affect large larvae but can kill small Protect fabrics by keeping them clean; materials out of reach of children and ones. However, cedar loses this oil as food and perspiration stains on fabrics pets, and don’t use these materials it ages. Having a tightly constructed attract carpet beetles. Thoroughly laun- where you store unwrapped food or chest is more important in the long run dering washable items in hot water or allow them to come into contact with than the type of wood used to make it. dry-cleaning them will kill all stages of food or cooking utensils. these insects. This is the most impor- Chemical Control tant method for controlling fabric pests Resin strips, which contain dichlorvos in clothing, blankets, and other wash- (DDVP) as the active ingredient, are Cleaning is always the best strategy; able articles. generally more effective in protect- however, if you have an area or article ing susceptible objects in enclosed that is infested that you can’t dry clean Regularly clean mounted animal speci- containers and provide longer control or launder, you can spray it with an mens such as museum pieces or game than PDB. If you use these products, insecticide. Find a product that lists trophies, or periodically place them be sure they are labeled for use inside carpet beetles on its label, and closely in a freezer for 10 to 14 days. Inspect homes. As these chemicals evaporate, follow the directions. Apply insec- stored woolens, linens, and furs, and they produce vapors that, in sufficient ticides as spot treatments, and limit air these items annually in the sun, concentration, will slowly kill insects. sprays to the edges of floor coverings, brushing them thoroughly. If you find The vapors build up to the required beneath rugs and furniture, on the an infestation, launder or dry-clean concentration only in an airtight con- floors and walls of closets, on shelving these items before returning them to tainer. If the items aren’t in an airtight where susceptible fabrics are stored, in storage. Be sure to seal cleaned items container, the chemicals will repel only cracks and crevices, and in other areas in a protective plastic bag or other suit- the adults; larvae already on the items that accumulate lint. Don’t spray cloth- able container. will continue to feed. Because some ing or bedding. resin strips contain oil, don’t let them Some furniture, mattresses, and pillows come into contact with the stored item. When treating attics, wall voids, and are stuffed with hair or feathers. When Also don’t use the resin strips in any other inaccessible places, use dust carpet beetles get into the stuffing, you area where people will be present for formulations such as boric acid (e.g., can’t control these insects simply by extended periods of time. Eatons Answer Boric Acid Insecticidal spraying the outside surface of the item. Dust). Don’t let borates come in contact The best way to eliminate the pests is to Generally, closets aren’t airtight and with objects containing natural dyes look for a pest control, dry cleaning, or are opened too frequently to hold in va- such as some Oriental rugs, sheepskins, storage firm that can treat the infested pors. However, you can turn a seldom- and bearskins. Also some dust for- item with lethal gas in a fumigation used closet into a suitable storage space mulations can adversely affect people vault. Because of the potential hazards by sealing cracks around the door with who have respiratory problems; read to the person applying fumigants, only tape or fitting the door with weather and follow label precautions carefully. licensed pest control operators can buy stripping. Seal cracks in walls and ceil- Professional fumigation might be and use them. Proper fumigation gives ings with putty or plastic wood. needed when infestations are extensive, quick, satisfactory control and kills all although the success rate will be lower stages of fabric pests. It doesn’t prevent A trunk, chest, box, or garment bag if the fumigant can’t penetrate all areas reinfestation, however. also makes a good storage container. where the carpet beetles are hiding.

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Closely inspect carpeted areas beneath heavy furniture and along carpet edges for infestation. If live larvae are found, spray both sides of infested carpet if at all possible, applying a lighter spray to the upper surface to reduce the possibility of staining. If the rug pad contains animal hair or wool and hasn’t been treated by the manufac- turer, spray it as well. It is better to wait until the rug has dried before putting any weight on it. If you are concerned that sprays might damage expensive broadloom or Oriental rugs, hire an experienced pest control operator or carpet-cleaning firm. Instead of insec- ticide treatment, area rugs can also be taken to dry cleaners who handle rugs.

Don’t use insecticides around open flames, sparks, or electrical circuits or spray them on asphalt or tile floors. Use only a light application on parquet AUTHOR: D.-H. Choe, Entomology, UC University of California scientists and other floors. On linoleums, first spray a small Riverside. qualified professionals have anonymously peer reviewed this publication for technical accuracy. The inconspicuous area and let it dry to see ANR Associate Editor for Urban Pest Management if staining occurs. TECHNICAL EDITOR: M. L. Flint managed this review process. To simplify information, trade names of products EDITOR: M. L. Fayard have been used. No endorsement of named products Applying protective sprays to furs is intended, nor is criticism implied of similar products isn’t recommended. If you store furs ILLUSTRATIONS: Table 1, D. Kidd (adults) that are not mentioned. at home during the summer, either This material is partially based upon work and V. Winemiller (larvae); and Figs. 1–3, supported by the Extension Service, U.S. Department protect them with moth crystals, flakes, D.-H. Choe. of Agriculture, under special project Section 3(d), or balls, or periodically shake and Integrated Pest Management. air them. Furs in commercial storage Produced by UC Statewide receive professional care, and you can Integrated Pest Management Program insure them against damage. University of California, Davis, CA 95616 This and other Pest Notes are available at Sometimes felts and hammers in pia- www.ipm.ucdavis.edu. nos become infested and so badly dam- aged that it affects the tone and action For more information, contact the University of California Cooperative Extension office in your of the instrument. Contact a piano county. See your telephone directory for addresses technician, who might recommend and phone numbers, or visit http://ucanr.org/ce.cfm. synthetic felt replacements. WARNING ON THE USE OF CHEMICALS Pesticides are poisonous. Always read and carefully follow all precautions and safety recommendations REFERENCES given on the container label. Store all chemicals in the original, labeled containers in a locked cabinet or shed, Mallis, A., D. Moreland, and S. A. Hedges. 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. 2011. The Mallis Handbook of Pest Control, Confine chemicals to the property being treated. Avoid drift onto neighboring properties, especially gardens 10th ed. Cleveland: GIE Publications. containing fruits or vegetables ready to be picked. 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 Moore, W. S., C. S. Koehler, and C. S. site. Contact your county agricultural commissioner for additional information on safe container disposal and Davis. 1979. Carpet Beetles and Clothes 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 Moths. Oakland: Univ. Calif. Agric. Nat. they may contaminate water supplies or natural waterways. Res. Publ. 2524. ANR NONDISCRIMINATION AND AFFIRMATIVE ACTION POLICY STATEMENT O’Connor-Marer, P. 2006. Residential, The University of California prohibits discrimination or harassment of any person in any of its programs or activities. The complete nondiscrimination policy statement can be found at http://ucanr.org/sites/anrstaff/ Industrial, and Institutional Pest Control, files/107734.doc. Inquiries regarding the university’s equal employment opportunity policies may be directed 2nd ed. Oakland: Univ. Calif. Agric. to Linda Marie Manton, Affirmative Action Contact, University of California, Davis, Agriculture and Natural Nat. Res. Publ. 3334. v Resources, One Shields Avenue, Davis, CA 95616, (530) 752-0495.

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