by David Moore
Manager of Technical Services and Board Certified Entomologist
with contributions by Eric Smith, PhD, BCE

 

The cool weather is upon us. It’s time to get out the sweaters, jackets, other woolens, and furs. Hopefully, you had them professionally dry-cleaned and placed in plastic bags before storage to reduce their attractiveness and accessibility to pests such as clothes moths and carpet beetles.

Oops, you say! You were in such a hurry that you forgot to do that. Ok, so what should you do now? Unfortunately, you are headed for a time-consuming process of going through all of your woolens looking for live/dead insects and insect damage. Let’s first look at the adult and larval stages of the webbing and casemaking clothes moths and then the varied and black carpet beetles, the two most commonly encountered of the carpet beetles. Then we’ll review the damage they cause and the signs of infestation that you need to look for on/in your woolens.

RECOGNITION

All of these pests are very small and will require the services of a pest management professional for positive identification. They can easily be confused with other small moths and beetles found in homes. So, be sure to collect and save pest samples for identification.

Casemaking and webbing clothes moths

  • Adults. These are small, about 3/8-1/2″ from wingtip to wingtip. The body and wings are buff to golden in color, but sometimes with a brownish tinge.
  • Larvae. Mature larvae are about 3/8″ long. They are whitish except for a brown head area.

Black and varied carpet beetles

  • Adults. These measure about 1/8-1/4″ long and are oval in shape. They are dark brown to black in color. Varied carpet beetles have in addition a pattern of yellowish/orangish and white scales on their upper surfaces.
  • Larvae. Larvae are up to 1/8″ long, and their upper surface is covered with numerous brownish hairs.

DAMAGE AND SIGNS OF INFESTATION

Casemaking clothes moth

  • The larvae are in cigar-shaped silken cases which are about 1/16-3/8″ long. These are open-ended and have pieces of the infested material incorporated into their surface.
  • The larvae are in cigar-shaped silken cases which are about 1/16-3/8″ long. These are open-ended and have pieces of the infested material incorporated into their surface.
  • The case containing the pupa is usually located in a crack or crevice, not in the infested material.

Webbing clothes moth

  • There are silken tubes in the hidden portions of clothes, such as under collars, or silken mats or patches on the material.
  • Both the tubes and mats have material fibers and feces incorporated into them.
  • Surface feeding/grazing and/or holes in the material are present.
  • In fur, the hairs are clipped at their base causing loose fur and exposed hide.

Webbing clothes moth

  • Fabrics typically have much surface damage and holes here and there, but the larvae can cause large irregular holes in material.
  • Furs have the hairs cut off at their base, but there is no damage to the hide.
  • Larval caste/molt skins are often present.

Varied carpet beetle

  • Fabrics typically have much surface damage and holes here and there, but the larvae can cause large irregular holes in material.
  • Furs have mostly the tips of the hairs damaged, leaving uneven areas.
  • Larval caste/molt skins are often present.

Control

First decision. You must decide if you want to keep the item or throw it away. This is based on what you found in terms of the amount of damage and the value of the item.

What to do for items to be kept if you found active/dead pests and/or damage:

  • Use a HEPA filter equipped vacuum, with hose attachment and crack & crevice wand/tool, to remove the dead and live pests, pest leavings (molt skins, larval/ pupal cases, powder/fecal droppings, and loose material), and any webbing.
  • If the items were not cleaned prior to storage, then if they are washable, wash with soapy water followed by a hot dryer (run for an additional 10 minutes after they are
    completely dry). If they are dry-clean only items, send them to the dry cleaner.
  • While these items are being cleaned, the storage area (closet, dresser drawers, chest, and/or wardrobe) must be thoroughly cleaned and then carefully treated with pesticide. It’s best to have a pest management professional select an appropriate pesticide and then apply it to the storage area or container.
  • If fabrics/furs are damaged, either repair the damage or have it professionally repaired.

Storage itself:

  • For furs, consult with a fur storage specialist for proper or acceptable cleaning and storage techniques.
  • Short or long-term storage preparation. Clean all items prior to storage. If they are washable, wash with soapy water followed by a hot dryer (run for an additional 10 minutes after they are completely dry). If they are dry-clean only items, send them to the dry cleaner.
  • Good. Store in tight-sealing plastic bags. Helps deny pest access.
  • Better. Store in vacuum storage bags. This will deny pest access and retards the development of any pests present due to limited oxygen being available.
  • Best. Store in vacuum storage bags with an oxygen scavenger/absorber inside. This will deny pest access and will kill any pests present, if the proper capacity oxygen scavenger/absorber is used, due to a lack of oxygen for life processes.

Monitoring

There are pheromone monitors available for both clothes moths and both of these carpet beetles. Consult with a pest management professional about availability and proper use.