Insect infestation is a common and often reoccurring problem with protein fibers such as wool in a home environment. Insects make no distinction between valuable textiles and utilitarian ones. Moths merely seek out opportune environments with ample protein to for nourishment, shelter, and reproduction.
The three most common insect infestations in wool textiles
Webbing Moths (Tineola bisselliella)
Webbing Moths are 5-7 mm long and golden in color are poor flyers and avoid light. The mature moths live for several weeks and lay eggs in dark undisturbed areas for example, under a sofa. The female can lay in excess of 100 eggs at a time and these eggs are barely visible to the human eye. When they hatch the larvae spin a cocoon to protect themselves from light and to provide adequate humidity control. They then consume protein fibers causing damage. The larval stage can last from several weeks to over a month at which point the larvae pupate into adult moths. Leaving behind a webbing material and small grainy excrement.
Casing moths (Tinea pellionella)
Casing moths are 7-8 mm when mature, golden in color and with dark spots on their wings. Casing moths spin a cocoon around their bodies. This casing is dragged around as they feed. Casing moths favor higher humidity than webbing moths and can tolerate cooler temperatures. Casing moths usually eat from the surface of a textile-like a pile rug whereas webbing moths will borrow. Once mature they leave behind the casing which is slightly larger than a grain of rice.
Carpet beetles (Anthrenus sp.)
Adult carpet beetles are 2-4 mm small round and similar in shape to ladybug but smaller with a white, black, brown, orange shell. The larvae have black-brown bristly hairs and typically eat in one area leaving round divots similar to small cinder burns from a fire.
Pest mitigation falls into five strategies
Avoidance. Avoid conditions that promote insect infestation. Keep textiles clean with regular vacuuming and washing. Many types of soils improve the environment for moths starches and oils raise the moisture level in wool making for a better moth environment. Before storage, textiles should at a minimum be vacuumed thoroughly and inspected for any signs of insects. Although washing is highly recommended and subsequent wrapping in a breathable product such as Tyvek or Heavy Kraft paper to inhibit soiling and infestations. Plastic should never be used for storing textiles.
Blocking insect entrance to the home. Often infestations enter the home via an open window or newly acquired textiles infested with eggs that subsequently hatch and spread to other textiles. Consider through cleaning or moth treatment of new textiles before they enter a home environment. Open doors and windows that allow easy access to textiles should be minimized.
Detection. Regular inspection of textiles is important, this can be done during rotating or routine vacuuming with care inspect dark undisturbed areas under a sofa and with hanging textiles on the back. Consider pheromone traps as a monitoring tool to determine when an infestation is present.
Confine. When an infestation is detected the infested textile should be removed from the home or confined (wrapped in plastic) to stop the spread of infestation to other textiles and treated as soon as possible.
Treatment. Removal of the textile from home and professional treatment is recommended. Commercial pesticide treatments and fumigates combined with wash are effective tools for killing moths and moth eggs.