Many believe moths eat silk, causing damage to textiles. However, adult moths are not the culprits; their larvae are responsible for feeding on materials.
The Real Culprits Behind Silk Damage
The culprits behind damage to silk and other natural fibers are the larvae of specific insect species, primarily clothes moths and carpet beetles. Adult moths, such as the common clothes moth (Tineola bisselliella) and the casemaking clothes moth (Tinea pellionella), cannot feed on fabrics; their role is reproduction. Damage occurs during the larval stage, as these creamy-white caterpillars (up to 1/2 inch long) consume fibers. Webbing clothes moth larvae often spin silken tubes or patches of webbing, while casemaking clothes moth larvae construct a portable silken case incorporating fibers from their food source.
Carpet beetle larvae also damage fabrics. Common species include the common carpet beetle (Anthrenus scrophulariae), the black carpet beetle (Attagenus unicolor), and the varied carpet beetle (Anthrenus verbasci). These larvae vary in appearance, often 1/8 to 1/4 inch long, tan to brownish, and bristly. They leave behind shed skins as they grow, a sign of their presence. Like clothes moth larvae, carpet beetle larvae are the destructive stage, while adult carpet beetles feed on pollen and nectar outdoors.
Why Silk and Other Fabrics Are Targeted
Larvae target silk and other natural materials because they contain keratin, a fibrous protein essential for their development. Keratin is abundant in animal-derived fibers such as wool, fur, feathers, and leather, making them primary food sources for clothes moth and carpet beetle larvae. They can also feed on human hair, pet dander, and other organic debris containing this protein. Larvae possess specialized mouthparts to chew and digest these natural fibers.
Synthetic fibers like nylon, polyester, and rayon are not food sources because they lack keratin. However, synthetics blended with wool or heavily soiled with food stains, body oils, or other organic residues can be attacked. Soiled items, especially with perspiration or bodily fluids, are particularly appealing to larvae. The ability of these larvae to digest keratin explains why they cause damage to a wide range of household items, from clothing and carpets to upholstery and taxidermy.
Safeguarding Your Textiles
Protecting textiles from these pests requires preventive strategies and monitoring. Proper storage is key: store clean garments in airtight containers or vacuum-sealed bags to prevent pest access. For long-term storage, breathable options like cotton bags or muslin are recommended for silk to allow air circulation. Cedar and lavender are natural deterrents, but their effectiveness is limited as volatile compounds dissipate over time.
Regular cleaning and maintenance of living spaces and textiles are important. Frequent vacuuming of carpets, rugs, and upholstered furniture helps remove eggs, larvae, and potential food sources like lint and pet hair. Clean clothing, especially natural fibers, before storage, as stains and body oils attract pests. Dry cleaning or hot water washing kills all insect life stages in fabrics. Periodically disturbing items by shaking or airing them out deters pests, who prefer dark, undisturbed areas.
Signs of an infestation include:
- Small, irregular holes in fabrics.
- Silken tubes or webbing.
- Small fecal pellets resembling sand or pepper.
- The presence of shed larval skins.
If an infestation is suspected, isolate affected items and thoroughly clean the surrounding area. Freezing infested items for several days kills larvae and eggs. Addressing infestations early minimizes damage to valuable textiles.