CARPET BEETLE
IDENTIFICATION AND LIFE CYCLE
All three carpet beetle species have similar life cycles . Adults lay eggs on a larval food source such as woolen fabric or carpets or furs. Eggs hatch in about two weeks, and the larvae feed for varying periods, depending upon the species and environmental conditions; they prefer dark, secluded places. When ready to pupate, the larvae might burrow further into the food or wander and burrow elsewhere. They might also pupate within their last larval skin if no other shelter is available. Although larvae don’t make webs as clothes moths do, their shed skins and fecal pellets, which are about the size of a grain of salt, make it obvious where they have been feeding.
Carpet beetle adults don’t feed on fabrics but seek out pollen and nectar. They are attracted to sunlight, and you’ll often find them feeding on the flowers of crape myrtle, spiraea, buckwheat, and other plants that produce abundant pollen. However, you can accidentally bring these pests inside on items such as cut flowers. With their rounded bodies and short antennae, carpet beetles somewhat resemble lady beetles in shape.
Varied Carpet Beetle
The adult varied carpet beetle, Anthrenus verbasci
, is about 1/10 inch long and black with an irregular pattern of white, brown, and dark yellow scales on its wing covers, or elytra. In older adults the scales that form this pattern wear off, so the beetles appear solid brown or black. Outdoors, female beetles search out spider webs or bee, wasp, or bird nests as places to lay their eggs. The nests and webs contain dead insects, beeswax, pollen, feathers, or other debris that can serve as larval food. Indoors, beetles deposit eggs on or near wool carpets and rugs, woolen goods, animal skins, furs, stuffed animals, leather book bindings, feathers, animal horns, whalebone, hair, silk, dried plant products, and other materials that can serve as larval food. Adults usually appear in spring or early summer; indoors, you’ll often find them near windows.
Mature larvae are slightly longer than adults and are covered with dense tufts of hair they extend upright to form a round plume if disturbed. They have alternating light and dark brown stripes and are distinguishable from other carpet beetle larvae because they are broader in the rear and narrower in front.
Furniture Carpet Beetles
When viewed from above, adults of the furniture carpet beetle, A. flavipes
, are slightly larger and rounder than the varied carpet beetle. Coloration and markings vary, but the furniture carpet beetle generally has a mottled appearance due to the black spots that intersperse the white and dark yellow to orange scales on its wing covers. If these scales have worn off, the adults can appear solid black. Their undersides are white.
Larvae are white at first but darken to dark red or chestnut brown as they mature. In contrast to larvae of the varied carpet beetle, these larvae are broader in front and narrower at the rear. Larvae of the furniture carpet beetle feed on the same types of items as varied carpet beetle larvae.
Black Carpet Beetle
Adults and larvae of the black carpet beetle, Attagenus unicolor
, are distinctly different from the carpet beetles described above. Adult black carpet beetles range from 1/8 to 3/16 inch long. They are shiny black and dark brown with brownish legs. Full-sized larvae can be as long as 5/16 inch and range from light brown to almost black. Larvae are shiny, smooth, and hard, while short, stiff hairs cover their body. Their body tapers toward the rear and ends in a tuft of long hairs. In California and other arid areas, the black carpet beetle is a more serious stored-product pest than a fabric pest.
DAMAGE
Damage occurs during the larval stage of carpet beetles. Larvae feed in dark, undisturbed locations on a variety of dead animals and animal products such as wool, silk, leather, fur, hair brushes with natural bristles, pet hair, and feathers; occasionally they feed on stored products such as certain spices and grains. They don’t feed on synthetic fibers.
It’s not always possible to tell from the damage whether clothes moths or carpet beetles caused it, but in general carpet beetles are more likely to damage a large area on one portion of a garment or carpet while moth damage more often appears as scattered holes. Also carpet beetle larvae leave brown, shelllike, bristly-looking cast skins when they molt. These skins and a lack of webbing are usually good clues that carpet beetles are the culprits.
All three carpet beetle species have similar life cycles . Adults lay eggs on a larval food source such as woolen fabric or carpets or furs. Eggs hatch in about two weeks, and the larvae feed for varying periods, depending upon the species and environmental conditions; they prefer dark, secluded places. When ready to pupate, the larvae might burrow further into the food or wander and burrow elsewhere. They might also pupate within their last larval skin if no other shelter is available. Although larvae don’t make webs as clothes moths do, their shed skins and fecal pellets, which are about the size of a grain of salt, make it obvious where they have been feeding.
Carpet beetle adults don’t feed on fabrics but seek out pollen and nectar. They are attracted to sunlight, and you’ll often find them feeding on the flowers of crape myrtle, spiraea, buckwheat, and other plants that produce abundant pollen. However, you can accidentally bring these pests inside on items such as cut flowers. With their rounded bodies and short antennae, carpet beetles somewhat resemble lady beetles in shape.
Varied Carpet Beetle
The adult varied carpet beetle, Anthrenus verbasci , is about 1/10 inch long and black with an irregular pattern of white, brown, and dark yellow scales on its wing covers, or elytra. In older adults the scales that form this pattern wear off, so the beetles appear solid brown or black. Outdoors, female beetles search out spider webs or bee, wasp, or bird nests as places to lay their eggs. The nests and webs contain dead insects, beeswax, pollen, feathers, or other debris that can serve as larval food. Indoors, beetles deposit eggs on or near wool carpets and rugs, woolen goods, animal skins, furs, stuffed animals, leather book bindings, feathers, animal horns, whalebone, hair, silk, dried plant products, and other materials that can serve as larval food. Adults usually appear in spring or early summer; indoors, you’ll often find them near windows.
Mature larvae are slightly longer than adults and are covered with dense tufts of hair they extend upright to form a round plume if disturbed. They have alternating light and dark brown stripes and are distinguishable from other carpet beetle larvae because they are broader in the rear and narrower in front.
Furniture Carpet Beetles
When viewed from above, adults of the furniture carpet beetle, A. flavipes , are slightly larger and rounder than the varied carpet beetle. Coloration and markings vary, but the furniture carpet beetle generally has a mottled appearance due to the black spots that intersperse the white and dark yellow to orange scales on its wing covers. If these scales have worn off, the adults can appear solid black. Their undersides are white.
Larvae are white at first but darken to dark red or chestnut brown as they mature. In contrast to larvae of the varied carpet beetle, these larvae are broader in front and narrower at the rear. Larvae of the furniture carpet beetle feed on the same types of items as varied carpet beetle larvae.
Black Carpet Beetle
Adults and larvae of the black carpet beetle, Attagenus unicolor , are distinctly different from the carpet beetles described above. Adult black carpet beetles range from 1/8 to 3/16 inch long. They are shiny black and dark brown with brownish legs. Full-sized larvae can be as long as 5/16 inch and range from light brown to almost black. Larvae are shiny, smooth, and hard, while short, stiff hairs cover their body. Their body tapers toward the rear and ends in a tuft of long hairs. In California and other arid areas, the black carpet beetle is a more serious stored-product pest than a fabric pest.
DAMAGE
Damage occurs during the larval stage of carpet beetles. Larvae feed in dark, undisturbed locations on a variety of dead animals and animal products such as wool, silk, leather, fur, hair brushes with natural bristles, pet hair, and feathers; occasionally they feed on stored products such as certain spices and grains. They don’t feed on synthetic fibers.
It’s not always possible to tell from the damage whether clothes moths or carpet beetles caused it, but in general carpet beetles are more likely to damage a large area on one portion of a garment or carpet while moth damage more often appears as scattered holes. Also carpet beetle larvae leave brown, shelllike, bristly-looking cast skins when they molt. These skins and a lack of webbing are usually good clues that carpet beetles are the culprits.
Eliminate the Source
Eliminate accumulations of lint, hair, dead insects, and other debris that serve as food for carpet beetles. Throw out badly infested items. Remove old spider webs and bird, rodent, bee, and wasp nests, which can harbor infestations. Examine cut flowers for adult beetles before bringing the flowers inside. And be sure that window screens, doors, and vents are secure to keep carpet beetles from flying in from outdoor sources.
Regular and thorough cleaning of rugs, draperies, upholstered furniture, closets, and other locations where carpet beetles congregate is an important preventive and control technique. Frequent, thorough vacuuming is an effective way of removing food sources as well as carpet beetle eggs, larvae, and adults. After vacuuming infested areas, dispose of the bag promptly, because it can contain eggs, larvae, or adult insects.
Protect fabrics by keeping them clean; food and perspiration stains on fabrics attract carpet beetles. Thoroughly laundering washable items in hot water or dry-cleaning them will kill all stages of these insects. This is the most important method for controlling fabric pests in clothing, blankets, and other washable articles.
Regularly clean mounted animal specimens such as museum pieces or game trophies, or periodically place them in a freezer for 10 to 14 days. Inspect stored woolens, linens, and furs, and air these items annually in the sun, brushing them thoroughly. If you find an infestation, launder or dry-clean these items before returning them to storage. Be sure to seal cleaned items in a protective plastic bag or other suitable container.
Some furniture, mattresses, and pillows are stuffed with hair or feathers. When carpet beetles get into the stuffing, you can’t control these insects simply by spraying the outside surface of the item. The best way to eliminate the pests is to look for a pest control, dry cleaning, or storage firm that can treat the infested item with lethal gas in a fumigation vault. Because of the potential hazards to the person applying fumigants, only licensed pest control operators can buy and use them. Proper fumigation gives quick, satisfactory control and kills all stages of fabric pests. It doesn’t prevent reinfestation, however.
Protecting Items in Storage
To properly store items that are susceptible to carpet beetles, first make sure the items are pest-free and clean, then place them in an airtight container, inserting a layer of paper every few inches. On these paper layers you can place insecticide-impregnated resin strips that are labeled for control of carpet beetles on fabrics, or you can use moth balls, flakes, or crystals, which contain paradichlorobenzene (PDB), also called 1,4-dichlorobenzene. Don’t let these materials come in direct contact with plastic buttons, hangers, or garment bags, since the active ingredients can cause the plastic to soften and melt into the fabric. Also be sure to keep these materials out of reach of children and pets, and don’t use these materials where you store unwrapped food or allow them to come into contact with food or cooking utensils.
Resin strips, which contain dichlorvos (DDVP) as the active ingredient, are generally more effective in protecting susceptible objects in enclosed containers and provide longer control than PDB. If you use these products, be sure they are labeled for use inside homes. As these chemicals evaporate, they produce vapors that, in sufficient concentration, will slowly kill insects. The vapors build up to the required concentration only in an airtight container. If the items aren’t in an airtight container, the chemicals will repel only the adults; larvae already on the items will continue to feed. Because some resin strips contain oil, don’t let them come into contact with the stored item. Also don’t use the resin strips in any area where people will be present for extended periods of time.
Generally, closets aren’t airtight and are opened too frequently to hold in vapors. However, you can turn a seldom-used closet into a suitable storage space by sealing cracks around the door with tape or fitting the door with weather stripping. Seal cracks in walls and ceilings with putty or plastic wood.
A trunk, chest, box, or garment bag also makes a good storage container. Seal any holes or cracks, and if the lid doesn’t fit tightly, seal it with tape, or wrap the entire container in heavy paper and seal it with tape.
Alternative methods for controlling carpet beetles include heating the infested object in an oven for at least 30 minutes at 120°F or higher or enclosing the object in a plastic bag and placing it in a freezer for 2 weeks at temperatures below 18°F. Before using either of these methods, consider if cold or heat will damage the object.
The effectiveness of cedar chests and closet floors made of cedar is debatable. Some cedar contains an oil that doesn’t affect large larvae but can kill small ones. However, cedar loses this oil as it ages. Having a tightly constructed chest is more important in the long run than the type of wood used to make it.
Eliminate accumulations of lint, hair, dead insects, and other debris that serve as food for carpet beetles. Throw out badly infested items. Remove old spider webs and bird, rodent, bee, and wasp nests, which can harbor infestations. Examine cut flowers for adult beetles before bringing the flowers inside. And be sure that window screens, doors, and vents are secure to keep carpet beetles from flying in from outdoor sources.
Regular and thorough cleaning of rugs, draperies, upholstered furniture, closets, and other locations where carpet beetles congregate is an important preventive and control technique. Frequent, thorough vacuuming is an effective way of removing food sources as well as carpet beetle eggs, larvae, and adults. After vacuuming infested areas, dispose of the bag promptly, because it can contain eggs, larvae, or adult insects.
Protect fabrics by keeping them clean; food and perspiration stains on fabrics attract carpet beetles. Thoroughly laundering washable items in hot water or dry-cleaning them will kill all stages of these insects. This is the most important method for controlling fabric pests in clothing, blankets, and other washable articles.
Regularly clean mounted animal specimens such as museum pieces or game trophies, or periodically place them in a freezer for 10 to 14 days. Inspect stored woolens, linens, and furs, and air these items annually in the sun, brushing them thoroughly. If you find an infestation, launder or dry-clean these items before returning them to storage. Be sure to seal cleaned items in a protective plastic bag or other suitable container.
Some furniture, mattresses, and pillows are stuffed with hair or feathers. When carpet beetles get into the stuffing, you can’t control these insects simply by spraying the outside surface of the item. The best way to eliminate the pests is to look for a pest control, dry cleaning, or storage firm that can treat the infested item with lethal gas in a fumigation vault. Because of the potential hazards to the person applying fumigants, only licensed pest control operators can buy and use them. Proper fumigation gives quick, satisfactory control and kills all stages of fabric pests. It doesn’t prevent reinfestation, however.
Protecting Items in Storage
To properly store items that are susceptible to carpet beetles, first make sure the items are pest-free and clean, then place them in an airtight container, inserting a layer of paper every few inches. On these paper layers you can place insecticide-impregnated resin strips that are labeled for control of carpet beetles on fabrics, or you can use moth balls, flakes, or crystals, which contain paradichlorobenzene (PDB), also called 1,4-dichlorobenzene. Don’t let these materials come in direct contact with plastic buttons, hangers, or garment bags, since the active ingredients can cause the plastic to soften and melt into the fabric. Also be sure to keep these materials out of reach of children and pets, and don’t use these materials where you store unwrapped food or allow them to come into contact with food or cooking utensils.
Resin strips, which contain dichlorvos (DDVP) as the active ingredient, are generally more effective in protecting susceptible objects in enclosed containers and provide longer control than PDB. If you use these products, be sure they are labeled for use inside homes. As these chemicals evaporate, they produce vapors that, in sufficient concentration, will slowly kill insects. The vapors build up to the required concentration only in an airtight container. If the items aren’t in an airtight container, the chemicals will repel only the adults; larvae already on the items will continue to feed. Because some resin strips contain oil, don’t let them come into contact with the stored item. Also don’t use the resin strips in any area where people will be present for extended periods of time.
Generally, closets aren’t airtight and are opened too frequently to hold in vapors. However, you can turn a seldom-used closet into a suitable storage space by sealing cracks around the door with tape or fitting the door with weather stripping. Seal cracks in walls and ceilings with putty or plastic wood.
A trunk, chest, box, or garment bag also makes a good storage container. Seal any holes or cracks, and if the lid doesn’t fit tightly, seal it with tape, or wrap the entire container in heavy paper and seal it with tape.
Alternative methods for controlling carpet beetles include heating the infested object in an oven for at least 30 minutes at 120°F or higher or enclosing the object in a plastic bag and placing it in a freezer for 2 weeks at temperatures below 18°F. Before using either of these methods, consider if cold or heat will damage the object.
The effectiveness of cedar chests and closet floors made of cedar is debatable. Some cedar contains an oil that doesn’t affect large larvae but can kill small ones. However, cedar loses this oil as it ages. Having a tightly constructed chest is more important in the long run than the type of wood used to make it.
