Clothes moths are tiny moths (about 6 mm), usually called moths, with hair or scales on their head. Two species attack clothing stored in the home: the webbing clothes moth and the casemaking clothes moth. Their narrow wings, with a long silky fringe, are golden or brownish, and spotted.
These are nighttime moths. The females lay their eggs in the dust in closets or attach them to the fibers of cloth using a gelatinous material. Tiny caterpillars emerge after a few days (the egg stage cannot survive the winter). The caterpillar weaves a tunnel of silk over the cloth where it feeds or builds a case of silk that it carries with it. Cloth fibers and excrement are incorporated into it. The caterpillar then either produces a silk case for metamorphosis or uses the one it is carrying, and installs it in the crack of a wall or of a ceiling. Inside, it first transforms into a chrysalis, then a moth. The caterpillar can live without nourishment for some time, and several weeks to over three years may go by between the caterpillar and the winged adult stages. The female dies when the egg-laying season is over. The male lives several weeks longer during which it continues to mate. All males can fly, but only a few females can do so. Other adults will run or jump. Some authors claim you can distinguish these tiny moths from those that infest food products by the fact that they avoid light and try to hide when disturbed.
Places where they can be found in the home
Flying adults are rarely seen since they are mainly active at night. The source of the infestation will be discovered in a fairly undisturbed place such as a box containing cloth stored for a long time or clothing worn from time to time.
In the caterpillar stage, clothes moths have enzymes that enable them to digest keratin. This protein is found in fur, hair, feathers, horns, hooves and nails. Inside the house, the caterpillars infest covers and pillows as well as clothing. They prefer animal materials such as woolens, but they can also make holes in cotton and linen as well as synthetic cloth impregnated with perspiration, food or grease from hair. They also attack grain, dairy products, meat, cayenne pepper and ginger, among other things. Furthermore, they may hide in vegetable substances in which they will not eat such as the foam used to stuff furniture. In nature, they also feed on pollen, ticks, dead insects, animal carcasses and snake exuviate (dead skin). They can also be found in bird nests, wild bee hives or under bark. On the other hand, once winged, the moth does not feed at all.
In the caterpillar stage, carpet moths dig galleries in carpet, wallpaper, and furniture stuffing, while the two moths described above live on the surface of cloth.
Install screens on doors and windows to prevent moths from entering the house.
Vacuum cracks in the floor and other places, such as underneath the furniture that is not moved often, and pipes.
Inspect clothing storage areas to see if moths are hiding there. Check whether caterpillars have made holes in clothing or have left their excrement behind. Also, check for the presence of silk tubes under the carpeting.
Before storing cloth, clothing, blankets or pillows, it is better to have them dry cleaned or washed and pressed. You can place them in containers (or put them in a large plastic bag or simply wrap them in brown paper) sealed with adhesive tape. Previously, the use of moth balls or paradichlorobenzene crystals was recommended, but to prevent the effects on human health, some people suggest using perfumed bars of soap or lavender sachets instead.
Second-hand clothing should be inspected before being brought into the home, and should be stored separately from new clothing.
Clothing that is not washed after every use, such as woolens, should not be stored in dark closets. It is a know fact that caterpillars cannot develop fully if given access only to clean woolens; however, they can rarely be clean enough to be protected against these insects. Caterpillars need the vitamin B found in human perspiration to complete their growth. Spots (juice, urine, perspiration) also enable them to obtain the salt they need. It is a good idea to hang woolens outdoors from time to time, to shake them out and to brush them. Carpets and furs should also be treated similarly or steam cleaned.
It would be best to use a specialized cold-storage company to store your fur coats. At home, the chosen place should be dry and cool, and the temperature should be lower than 7°C to prevent clothes moths from developing.
Furthermore, a moth killer formulation has been previously used. It is incorporated into clothing in the wash and its purpose is to protect woolens from infestation for at least one year.
Make sure no trapped mouse or squirrel carcasses are the source of the problem. Find and destroy any bat shelter or abandoned bird, mouse or wasp nest.
Vacuum to remove larvae that hide in floor openings and seal every crack.
Adults can be trapped using an inverted jar with cardboard underneath. You can also use the sticky tape sold to trap flies, or cardboard sticky traps. The latter would be more effective if combined with sardine oil, for example. A synthetic pheromone that mimics the one the female releases to attract the male can also be added to these traps. They will then be useful for detecting the presence of these insects or controlling small infestations.
When clothing is infected, take it outdoors and brush it to destroy the fragile eggs and dislodge the caterpillars. They will not survive if the clothing is exposed for two or three hours to sunlight in summer (according to some) or if a room is heated to 37°C for one week or 41°C for four hours. They can also be subjected to sub-zero temperatures by placing them outdoors or freezing them for two or three days, or subjecting them to large temperature differences. Microwave treatments have also proven to be somewhat effective.
Only heavy infestations may require the use of pesticides. Preferably, diatomaceous earth should be used. It scratches the body of the caterpillars that then die of dehydration. There are also other options (permethrin). Atmospheric treatments have sometimes been necessary in the case of major infestations.
In caterpillars, silk thread emerges from the “mouth” while in spiders, the spinnerets are located at the rear of the body.
Moths that infest clothing are called “clothes moths”, but in French they are commonly called “mites”. In English, the term “mites” does not refer to these moths, but describes some acarina, such as those that cause dust allergy, instead.
Some people believe that mothballs (naphthalene), like paradichlorobenzene, REPEL insects, but this is false. If these chemicals are placed in a clothing bag or box hermetically sealed with adhesive tape, the vapours will reach the level of toxicity needed to kill the moths and young larvae, but it will not affect the other stages of development. Camphor (natural or synthetic) would actually have a repulsive effect and would be less toxic for us, but it would be less effective in killing clothes moths than the other two chemicals. Cedar oil cannot be considered a repellent, but it acts on the very young larvae. Note, however, that this oil only remains for a few years inside dimension stock wood and, consequently, in chests or closets made of it.
The fact that a chemical product is well-known, has been used for a long time, and can readily be obtained does not necessarily mean that is it completely harmless to humans. Among other things, moth balls have sometimes caused foetal contamination following exposure of the mother, and systemic reactions (throughout the body) in children after wearing clothing that had been stored with this product. Some authors recommend avoiding the use of paradichlorobenzene nowadays since it could cause cancer. It should be noted that the insecticides usually sold in the form of pulverizer are not a pledge of quality for the domestic use. It would be preferable to have recourse to a professional exterminator in order to know the suitable products for the type of insect to be eliminated.