Carpet beetles, belonging to the dermestid beetle family, are common household pests. The name "carpet beetle" originated when most carpets were made of wool, a primary food source for these insects. While adult carpet beetles primarily consume pollen and nectar, it is the larvae that cause damage by feeding on a variety of materials. This article provides a detailed overview of the carpet beetle diet, the types of damage they cause, and effective prevention and control methods.
Identifying Carpet Beetles
Carpet beetles have rounded bodies and short antennae, resembling smaller, differently colored ladybugs. Their shells exhibit stripes of black, white, yellow, or orange. Adults range from 1/16 to 1/8 inch in size, similar to bed bugs, which can lead to misidentification. Carpet beetle larvae are even smaller, measuring about 1/8 to 1/4 inch long.
Common Types of Carpet Beetles
Several types of carpet beetles can infest homes, each with unique characteristics:
- Varied Carpet Beetle (Anthrenus verbasci): The adult varied carpet beetle is small (2-3 mm), oval to round, with splotches of white and yellow, giving it a gray calico pattern. Mature larvae are slightly longer than adults and covered with dense tufts of hair that extend upright into a round plume when disturbed.
- Furniture Carpet Beetle (Anthrenus flavipes): Adults are slightly larger and rounder than varied carpet beetles, with mottled coloration due to black spots interspersed with white and dark yellow to orange scales on their wing covers. Larvae are white initially, darkening to dark red or chestnut brown as they mature, and are broader in front, narrowing at the rear.
- Black Carpet Beetle (Attagenus unicolor): Adult black carpet beetles range from 1/8 to 3/16 inch long and are shiny black or dark brown with brownish legs. Larvae can grow up to 5/16 inch long, ranging from light brown to almost black, with a body that tapers toward the rear and ends in a tuft of long hairs.
Life Cycle
All carpet beetle species undergo a complete metamorphosis, progressing through four stages: egg, larva, pupa, and adult. Adult carpet beetles lay eggs on food sources such as furs, woolen fabric, and carpets. The eggs hatch in about two weeks under typical indoor conditions (room temperature: 25-26°C or 77-78°F). The larvae feed for varying periods, depending on the species and environmental conditions, preferring dark, secluded places. When ready to pupate, larvae may burrow further into the food source or wander elsewhere, sometimes pupating within their last larval skin if no other shelter is available.
Diet of Carpet Beetles
Carpet beetles have a wide variety in their diet, and carpet is just one of the many things they eat. Adult carpet beetles primarily feed on pollen and nectar from outdoor sources, especially plants with white or cream-colored flowers, such as spirea and crepe myrtle. They cause no damage to fabrics.
Read also: What Do Carpet Pythons Eat?
Larval Diet
Carpet beetle larvae are the primary cause of damage in homes, feeding on materials containing keratin, a fibrous protein found in animal-based products. Their non-synthetic material diet usually consists of things like animal furs, silk, leather, wool, and other animal based products. Common food sources include:
- Wool
- Fur
- Felt
- Silk
- Feathers
- Skins
- Leather
- Hair (including pet hair and dander)
- Horns
- Antlers
- Taxidermy specimens
- Carrion
- Dead insects
While larvae prefer organic materials, they will consume synthetic fibers with oil, perspiration, and food stains. Some varieties of carpet beetle will also infest seeds, cereals, pet food, and other plant-based materials. They sometimes feed on grains and spices, as well as nuts, cereals and other milled products.
Damage Caused by Carpet Beetles
Carpet beetle larvae cause damage by feeding 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.
Types of Damage
- Fabrics: Irregular holes in clothing, carpets, rugs, upholstery, and other textiles. The larvae often feed within fabric folds (hems, collars, cuffs, etc.) in closets, chests, and boxes where items are stored for long periods.
- Household Items: Damage to sweaters, scarves, coats, blankets, down pillows and comforters, upholstery, toys, decorative items, and taxidermy mounts.
- Other Materials: Infestation of seeds, cereals, pet food, and other plant-based materials. They may also damage felts and hammers in pianos, affecting the instrument's tone and action.
Signs of Infestation
- Visible Larvae: Finding larvae crawling in concealed locations along baseboards, under furniture, or in little-used drawers and storage areas. The tiny larvae have tufts of dark hair which they raise when disturbed.
- Shed Skins: The developing larvae leave behind shed (molted) skins, which are brown, shell-like, and bristly-looking.
- Damage to Materials: Noticing irregular holes and grazed areas on fabrics and other susceptible items.
- Adult Beetles: Spotting adult carpet beetles crawling on walls, especially in springtime, or finding them on windowsills.
- Fecal Pellets: Identifying fecal pellets, which are about the size of a grain of salt, in areas where larvae have been feeding.
Preventing Carpet Beetle Infestations
As with clothes moths, the best way to avoid problems with carpet beetles is prevention. Sanitation is very important.
Good Housekeeping Practices
- Regular Vacuuming: Thoroughly vacuum carpeting, along baseboards, under furniture, and in closets. Frequent, thorough vacuuming is an effective way of removing food sources as well as carpet beetle eggs, larvae, and adults.
- Cleanliness: Eliminate accumulations of lint, hair, dead insects, and other debris that serve as food for carpet beetles.
- Proper Storage: Woolens and other susceptible items should be dry-cleaned or laundered before being stored for long periods. Cleaning kills any eggs or larvae that may be present, and removes perspiration odors that tend to attract pests. Items susceptible to attack by clothes moths and carpet beetles should be kept clean and tightly sealed in plastic bags or containers when not in use.
- Inspect Items: Examine cut flowers for adult beetles before bringing the flowers inside. Regularly clean mounted animal specimens such as museum pieces or game trophies, or periodically place them in a freezer for 10 to 14 days.
- Remove Nests: Remove old spider webs and bird, rodent, bee, and wasp nests, which can harbor infestations.
- Air Items Regularly: 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.
Additional Preventive Measures
- Seal Openings: Carpet beetles usually enter the home through openings along windows and doors. Newly hatched larvae are tiny and can easily enter through cracks less than one-sixteenth of an inch wide.
- Monitor with Traps: Sticky traps provisioned with or without an attractant lure are also useful for detecting infestations. The traps are often effective at revealing infestations in the early stages when the pests are hard to find by inspection alone.
- Check Flowers: Carpet beetles frequently fly into homes from flowers in the landscape.
Controlling Carpet Beetle Infestations
To eliminate carpet beetles, you must locate all infested items. Carpet beetles prefer to dwell in dark, undisturbed areas where susceptible items are stored for long periods.
Read also: Spider Beetle Identification
Locating Infested Items
- Clothing: When inspecting clothing, pay attention to seams, folds, and creases (e.g. cuffs and collars) where larvae often prefer to feed.
- Carpets and Rugs: Larvae also tend to infest the lower edges of rugs and carpeting. Use needle-nose pliers to lift the outer edge of wall-to-wall carpet from the tack strip along baseboards.
- Upholstered Furniture: Check under/within upholstered furniture.
- Vents and Ducts: Inspect inside floor vents and ducts with accumulations of pet hair and lint.
- Other Areas: Look for bird nests, animal carcasses, or accumulations of dead insects in attics or elsewhere.
Elimination Methods
- Cleaning and Disposal: Once found, infested items and susceptible articles nearby should be laundered, dry-cleaned, or discarded. Bagging heavily infested items before disposal can help prevent further spread of the beetles. Dry-cleaning or hot laundering kills any eggs or larvae that may be present. Heat generated by a clothes dryer is effective as well.
- Vacuuming: Vacuuming floors, carpets, and inside heating vents effectively removes larvae as well as hair and lint, which could support future infestations.
- Thermal Disinfestation: Infested items can be disinfested more effectively utilizing a household, chest, or walk-in freezer. In order to kill carpet beetles and clothes moths, infested items need to be held at minimum temperature of 0 degrees Fahrenheit for at least one week.
- Insecticides: Insecticides applied to infested rugs and carpets may be helpful as a supplement to good housekeeping. Sprays recommended for flea control, or with fabric insects listed on the label are effective. When treating, pay particular attention to carpet edges, floor/wall junctions, beneath furniture, and bottoms of closets.
Professional Assistance
- Pest Control Services: Removal of carpet beetles on your own can be very difficult, and in most cases, you will need to hire a pest control service to eliminate them from your home.
- Fumigation: 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.
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