Carpet Beetles

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 materials 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.

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