Updated: Nov 20
Wool Moths, the enemy of your rug!
Insect infestation is a common and often reoccurring problem in home environments.
Insects make no distinction between valuable textiles and utilitarian ones. Wool moths seek opportune settings to infest textiles for shelter, reproduction, and in the case of some months and beetle species for food.
The protein and moisture content of protein textiles such as wool is what these insects seek. Since these insects have no other source of hydration, moisture content and humidity play an essential part in infestations.
Most household soils contain proteins, oils, and starches which are mostly hydrophilic (moisture-loving); as such, elevate the moisture level of proteins fibers making textiles a more favorable environment. Therefore, Soiled textiles make for a more hospitable environment for infestation with higher moisture levels and additional sources of nourishment for insect larvae development.
Know the enemy of wool 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 more than 100 eggs at a time, and these eggs are barely visible to the human eye. The larvae spin a cocoon when they hatch to protect themselves from light and provide ad
equate humidity control. They then consume protein fibers causing damage. The larval stage can last from several weeks to over a month. At this 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 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 feed on wool; they are 2-4 mm oval-shaped brown or black in color, and similar in shape to ladybugs. The larvae have black-brown bristly hairs and carpet beetle infestation and typically eat in one area, leaving round divots similar to minor cinder burns from a fire. The larvae feed on protein fibers in rugs and upholstered furniture.
Protecting wool Rugs from moths, steps to pest mitigation
Weekly vacuuming of textiles to remove the build-up of soils such as dander pet hair help reduce the possibility of wool moth and carpet beetle infestations. As mentioned before, many household soils are protein-based and hydrophilic (moisture-loving), and these soils on your wool carpets make for a more hospitable environment for infestation. Vacuuming helps reduce this soil, and timely cleaning of oriental rugs and carpets is a pest mitigation method.
Regular inspection of textiles is essential. This is easily done during rotating or routine vacuuming. Ensure you inspect dark, undisturbed areas under a sofa and hanging textiles on the back. Remember, moths seek out dark, undisturbed areas. Consider pheromone traps as a monitoring tool to determine when an infestation is present. Bear in mind that these traps don't kill all wool moths; they attract male moths. Traps are monitoring tools, a sort of bug fire alarm to let you know moths are in your home.
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 soon as possible.
If you have a moth infestation and damage to a rug in your home, it's most likely that moths have infested and laid eggs in other rugs. Your home has an infestation, not just one rug. Failure to address possible infestation in all rugs results in repeated moth outbreaks in the home.
Time to call a professional, licensed pest control service and get the rugs out of the home and treated for months. Launder all protein fiber clothes wool, alpaca, and feather times.
We suggest any items not in use be wrapped in a breathable material, an old bed sheet, Paper or Tyvek to deny moths access to wool oriental rugs
Treatment for wool moths that work
Freezing is an effective method to control an active infestation. It's generally recognized that temperatures of -20 C. (-4.F) are needed to ensure eggs are killed for one week. Home freezers typically don't reach these temperatures.
Often textiles are allowed to thaw for several days and multiple treatments or freezing and warming to shock any survivors of the initial freeze. Wet textiles should be dried first before freezing to reduce the possibility of damage from water ice expansion and crystallization.
Temperatures of 45 C. (113 F.) have been shown to kill insects in all stages of development in several hours. The textile temperature must reach these temperatures, not simply the room the textiles are in. The two-hour treatment should begin when the textiles have reached 45C. (113F.)
Steam from an iron or clothes steamer is very effective and useful on small thin textiles such as tapestries, kilims, and Navajo rugs. Thick pile rugs are difficult to steam and ensure the core of the rug is hot enough to kill moth larvae and eggs.
The use of washing as a treatment has shown minimal effectiveness by itself—however, hot water 120. F and steam, particularly with pretreatment of insecticides, are effective, but the risk of a color run, shrinkage, and felting, so this method has limitations for wool rugs and textiles. Careful consideration should be given before putting textiles through this process.
Dry cleaning solvents are effective, particularly when combined with heat; the limitation is the size of the rug or textile and the fragility and condition of the rug or textile to be treated. large rugs cannot be dry cleaned effectively.
-Moth ball/crystals (Naphthalene, para-dichlorobenzine).
Work in enclosed environments in high concentrations. Carpet beetles are not as sensitive as webbing & casing moths. Additionally, long-term exposure can cause staining and discoloring with some textiles. The mothball odor permeates rugs and is objectionable to some, and requires washing to remove. Mothballs are less than ideal in a home environment.
Pesticides effectively deal with adult moths and larvae but not unhatched eggs. As such multiple treatments are required to break the life cycle of moths and ensure eradication. Moth eggs are hard to kill, and successful treatment must address all stages of the moth life cycle.
-Commercial chemical treatments
Microban is often used commercially to treat moth-infested rugs. Applied to the front and back of wool rugs, which is then typically rolled up and placed in a plastic tube for 24 hours and subsequently dusted and washed, this has been shown to be effective. Not for use in home environments, and rugs and textiles must be cleaned after treatment.
Neem oil is not a pesticide in the classic sense. It does not directly kill insects. Neem oil disrupts an insect's life cycle by blocking and altering hormones from working properly. Insects forget to eat, mate and stop laying eggs. While effective and safe, Neem is slow to work the smell and oily residue objectionable and attract soils.
What doesn't work to control wool moths in Wool oriental rugs?
Below are examples of methods that may provide some ancillary benefits but do not stop pest infestations.
-Cedar oil, woodblocks, or shavings
-Airing out textiles in sunlight
-Tobacco, Lavender, or other dried plant herbs, oils, or leaves rolled in with a rug.
-Wrapping in newspaper
The above methods may have some mild benefits; over the years, we have pulled textiles with active moth infestation out of cedar chests and rugs dusted with tobacco leaves. These things DO NOT WORK. Relying on old wives' tales and home remedies from the internet results in more and continued damage and destruction to oriental rugs and other protein-fiber textiles.
How to keep your home moth free
Emphasis should be placed on treating new rugs and textiles, entering the home with carful Inspection and cleaning that new thrift store or antique rug purchase or wool sweater.
Monitor your home with wool moth pheromone traps; if moths are detected, take quick action and call a pest control company.
Weekly vacuuming, visual inspection, particularly dark areas under a sofa or bed, and timely washing of textiles and wrapping textiles before storage.
Don't toss rugs in your garage or basement during that 6-month remodel. Instead, wrap them or have the rugs professionally cleaned and wrapped. Some companies like Renaissance Rug Cleaning will pick up your rug, clean it, and hold the rug during a remodel or deliver back wrapped.
More about wool moths can be found on our web pages