Q: I found a few small moths in a spare bedroom where I store wool fabric for my rug hooking handiwork. I’m concerned that these might be clothes moths because they look much smaller than meal moths I’ve seen in the past in the kitchen. What should I do?
A: Clothes moths are small moths that feed in the larval (caterpillar) stage, primarily on wool fibers. This can include wool fabric, clothing, blankets, carpets, upholstered furniture or even wool felt pads in pianos. Fur and feathered items can also be damaged. Cotton or synthetic fibers will sometimes be damaged if these fabrics also contain wool. Soiled or stained fabrics are particularly attractive to clothes moths.
Adult clothes moths are weak fliers that are not attracted to lights, so they are rarely seen throughout the house away from infested items. In contrast, Indian meal moths are larger (about ⅜ inch in length, compared with the ¼-inch-long clothes moth) and are attracted to lights, including lamps and televisions.
Damage from clothes moths commonly occurs on collars, cuffs or in other hidden areas such as fabric folds. Periodically examine and air out stored items, hanging them in the sun. Brush fabric surfaces, seams and pockets to dislodge eggs and larvae.
Properly storing clothes and fabrics can prevent clothes moth infestations. Fabrics should be clean and free from odors and stains before storage. Dry cleaning will kill all stages of the clothes moth, as will laundering for 30 minutes in water that is at least 120 degrees. Heating items to 120 degrees for 30 minutes or more, or deep freezing below 18 degrees for several days will also kill clothes moths. Store clean items in tightly sealed plastic containers.
Q: I’ve seen a tan-colored moth flying in a zigzag pattern around my living room lights. Since my living room is not next to my kitchen, I’m sure this can’t be a pantry pest, but what is it?
A: At some point, nearly everyone has problems with the Indian meal moth, which is commonly brought to the home through infested packaged foods, birdseed or dog food. Contaminated foods can bring eggs or caterpillars into the pantry.
Adult meal moths may be seen anywhere in the home, not just in the kitchen. An adult meal moth is a more-than-gentle suggestion that some changes are needed in cleaning and food storage practices.
As they feed, the caterpillars spin messy silk in their food. The caterpillars then form small cocoons under shelves or in cracks and crevices in the pantry. Adult moths later emerge; females can lay 60 to 300 eggs, which can mature in as little as four weeks, quickly building up the household population.
Unfortunately, a kitchen can maintain an infestation of Indian meal moths without many obvious signs. The caterpillars feed out of sight, and the well-hidden cocoons are small and white, often tucked back into rarely-seen corners of cabinets and pantries. The most obvious sign of the Indian meal moth is the adult flying in a zigzag pattern through the home, resting on walls or attracted to lights.
When my daughter was in middle school, she took an interest in baking, and would scour through her grandmother’s cookbooks for new recipes to try. She was curious why recipes from older cookbooks always called for sifting flour, while few modern recipes do. One of the main reasons for sifting flour was to remove insects, insect parts and webbing before baking. Modern milling and storage practices have reduced the occurrence of insects in flour and other foods, but meal moths, book lice, drugstore beetles and other insects still create problems in the kitchen.
Preventing insect infestations is easier than trying to find the source of infestation and clear up a problem, so consider following these food storage guidelines:
• Inspect products before purchase, taking careful note of expiration dates.
• Avoid all damaged packaged food. Inspect plastic and cardboard containers before storage, since meal moth caterpillars can easily chew through this material.
• When purchasing bulk or seldom-used foods, only purchase as much as will be used in a few months’ time, and store these products in hard plastic or glass containers. Herbs or spices can be stored in the refrigerator, and other seldom-used foods can be stored in the freezer.
• Make a habit of storing flour, oats barley and other grains in hard plastic or glass containers with tight-fitting lids, particularly if these foods are seldom-used.
• Establish a regular cycle of cleaning to prevent pantry items from harboring pests. Items not used in six months should be eaten, frozen, given away or thrown out.
• Food suspected of infestation can be put into the freezer (0 degrees) for four to seven days. Freezing temperatures will kill all meal moth life stages. After freezing, foods can then be stored in hard plastic or glass until used, although sifting may be necessary.
• Store birdseed in a container with a tight-sealing lid, in the garage (not the house) if possible.
• Pet food should also be stored in hard plastic containers with tight-sealing lids.
• Careful and regular cleaning of all food storage areas is essential. Meal moths can survive on very little food, including crumbs or small amounts of spilled flour or cereal. Clean all shelves, top to bottom, with hot soapy water. Pay careful attention to cracks and crevices, where cocoons are likely to hide.
• Decorative items in the home, such as wreaths or flower arrangements with decorative wheat or corn can be an important and often overlooked source of infestation. Periodically deep freeze these items, or limit their use indoors to a few months before cycling them to outdoor areas or composting them.
Q: I’ve seen dark gray moths flying around a seldom-used drain in the basement. What is it, and what should I do?
A: Drain flies, also known as moth flies, sometimes appear suddenly in homes. Adult flies accumulate around showers, bathtubs, sinks and floor drains, especially in the basement. The eggs, larvae and pupae can be found in the bacterial muck, slime, or gelatinous film that accumulates on the sides of drains.
The most effective way to prevent drain fly infestations is to eliminate breeding places. Bacterial scum serves as the food source for developing larvae. This scum needs to be removed from drain pipes, drain traps, and other plumbing structures. Cleaning is best done by using an enzyme-action product that is designed to break the sticky bond that bacteria and algae form on the pipes (the so-called scum). A stiff, long-handled brush can aid in the removal of scum from pipes and traps.
Bleach is not recommended to remove the scum; drain flies are surprisingly resistant to bleach. Aerosol insecticides, bug “bombs” or other insecticide treatments are not effective and are not recommended to manage this pest.
Denise Ellsworth directs the honeybee and native pollinator education program for the Ohio State University. If you have questions about caring for your garden, contact her at 330-263-3700 or click on the Ask Denise link on her blog at www.osugarden.com.