Common Name. Case making clothes moth
Scientific Name. Tinea pellionella
This species is less commonly encountered and of far less economic importance than the webbing clothes moth. Its common name comes from the silken case spun by the larva and which is carried about wherever the larva goes. The case making clothes moth is worldwide in distribution, but is more common in the southern United States.
Case making clothes moths measure about 3/8 to 1/2 inch from wing tip to wing tip; both the forewings and hind wings are long and narrow. Both the body and wings are buff to golden with a brownish tinge, except for 3 dark spots on each front wing, which may be indistinct or rubbed off with age. The hind wings are fringed with long hairs. The mature larva is 3/8 inch long and clear white except for the brown head and first thoracic segment.
(1) The webbing clothes moth (Tineola bisselliella) lacks the 3 dark spots on the forewing and has a reddish tuft on its head. (2) The Indian meal moth (Plodia interpunctella) has front wings with the inner 1/3 (by the shoulder) buff colored and the outer 2/3 coppery-bronze. Its wingspan is 5/8 to 3/4 inch.
Damage and Signs of Infestation
The silken cases of the larvae are cigar-shaped, open-ended, 1/16 to 3/8 inch long and have fragments of infested material incorporated into the case. They are usually attached to the material at one end and contain the larva. Surface feeding occurs in irregular furrows or holes if infestation is severe. The case containing the pupa is usually located in a crack or crevice, not on the infested material.
Females mate on the day they emerge as adults and can start laying eggs the next day. They lay an average of about 37 to 48 eggs (range 8 to 83) singly on suitable larval food. The eggs hatch in 4 to 7 days and the larva wanders about for 24 hours. The larval stage lasts about 33 to 90 days depending on the temperature and humidity, during which there will be 5 to 11 molts.
The mature larva seeks a sheltered place to pupate and pupation lasts about 9 to 19 days depending on the temperature. Development time (egg to adult) takes from 46 to 116 days. Female adults live about 3 to 8 days and males live about 3 to 5 days.
Case making clothes moth larvae attack primarily materials of animal origin and secondarily those of plant origin. Animal-origin materials include feathers, woolens, rugs, furs, mummified carcasses, taxidermy mounts and piano felts. Plant-origin materials include tobacco, various herbs and seasonings, hemp, various plant-based drugs, linseed, almonds saffron, etc. It is particularly a pest of feathers/down, hair and fur.
The larva moves by extending its head and thoracic legs out of its case and then drags the case along. It can feed from either end of the case. The larva usually grazes here and there; causing only surface furrows but may occasionally cause holes by feeding in one place for some time. It rarely spins silk on the material. When it is ready to pupate, the larva seeks a protected place, such as a crack or crevice, which is usually off the infested material.
Adults (moths) do not feed. They shun light, not being attracted to lights as are most moth species. The males are smaller and are active fliers; whereas, the females are sluggish and fly only short distances.
Cultural Control And Preventative Measures
Garments and accessories comprised of wool, felt, fur and feathers should be dry cleaned after each use and stored in airtight garment storage bags or boxes. Refrigerated storage is effective as well. Upholstered furniture, blankets, carpets and rugs comprised of wool should be professionally cleaned and treated with an insecticidal protectant (e.g., borate or permethrin ingredient) where available. Pet hair and fur should be vacuumed weekly from floors and furniture.
Taxidermy specimens and other dried animal products should be treated with an appropriate protectant or stored in pest-proof (air-tight) containers/display cases or discarded altogether. Likewise, botanical materials susceptible to attack by these moths should be stored in protective containers or displays.
The key to control is proper identification, a thorough inspection, good sanitation and pesticide application when required. A Rottler technician will inspect for sources of infestation throughout the premises. All infested items will be identified for the customer to have professionally cleaned and, where available, treated with a protectant. The technician may perform spot treatments within closets and other infested rooms using an aerosol or liquid insecticide.