Moths belong to the order Lepidoptera, which also includes butterflies. They undergo complete metamorphosis, transitioning through four life stages: egg, larva, pupa, and adult. Their dietary needs change significantly depending on their developmental stage.
Adult Moth Feeding Habits
Many adult moths primarily sustain themselves on liquids, using a proboscis to sip nectar from flowers for energy. Some species also consume tree sap, juices from rotting fruits, or honeydew from aphids. These liquid diets mainly support flight and reproduction. However, some adult moths, particularly those with short lifespans, do not feed, relying on energy reserves from their larval stage.
Caterpillar Diets: The Primary Eaters
Caterpillars, the larval stage, are where most of a moth’s feeding and growth occurs. They are voracious eaters, consuming much food to fuel their rapid development. Most caterpillars are herbivorous, primarily feeding on plant material such as leaves, stems, flowers, and roots. Some species are generalists, eating a wide variety of plants, while others are specialists, restricting their diet to specific plant types.
While plant material is their primary diet, some caterpillar species have unusual feeding habits. Certain caterpillars may consume fungi or detritus. Some are carnivorous, preying on small insects like aphids or other caterpillars. Additionally, some feed on animal waste like dung or bird droppings.
Identifying Common Moth Pests by Their Diet
Damage attributed to moths in homes is primarily caused by their larvae, whose specific dietary preferences make them household pests.
Clothes Moths
The larvae of clothes moths, including the webbing clothes moth (Tineola bisselliella) and the casemaking clothes moth (Tinea pellionella), are known for consuming natural fibers. They target materials containing keratin, a protein in animal products such as wool, silk, fur, feathers, and leather. These larvae often prefer soiled fabrics, which provide additional nutrients or moisture. While they primarily feed on natural fibers, they may also consume synthetic or cotton fabrics if blended with wool or heavily soiled. Casemaking clothes moth larvae are known for carrying a protective silken case made from the fibers they consume.
Pantry Moths
Pantry moths, including the Indianmeal moth (Plodia interpunctella) and the Mediterranean flour moth (Ephestia kuehniella), infest a wide range of dry stored food products. Their larvae feed on items such as grains, cereals, flour, pasta, nuts, and dried fruits. They also infest pet food, birdseed, spices, and chocolate. Pantry moth larvae spin silken webs within infested food, clumping items and contaminating them with droppings and shed skins. The Mediterranean flour moth is known for producing much webbing that can clog machinery in flour mills.
Carpet Moths
Carpet moths share similar dietary habits with clothes moths. Their larvae primarily feed on keratin in natural animal fibers, commonly infesting wool carpets, rugs, and upholstery. They can also damage other natural materials such as fur, silk, and felt. While their name suggests a focus on carpets, they consume any keratin-rich material. The larvae create threadbare patches and holes in these materials.