The mill moth (Ephestia kuehniella) is a common pest in food storage areas. Also commonly known as the Mediterranean flour moth, it’s often found in mills, warehouses, and sometimes homes, especially where flour or grain is stored. These moths are more than a nuisance; their larvae can contaminate food and cause costly damage.
Adult — 1/4"—3/8" in length with a wing span 5/8"—3/4". Black zig zag pattern across the wings which are gray.
Larva — pinkish or greenish tinge depending on food eaten. Brown head. Lives within a silken tube.
152 days at 17°C, 42 days at 30°C. Prolific silk spinner. Adults live about 2 weeks.
Rarely attacks commodities other than flour. Adults tend to rest during the day and fly at dusk.
Mill moths are prolific silk spinners, known for their quick reproductive cycle and ability to infest dry food products. While the adult moths don’t eat, their main role is to reproduce. Females lay large numbers of eggs directly in or near food sources like flour, grains, and cereal, and once the eggs hatch, the larvae begin feeding right away.
As with most moths, the larval stage is the one that does the damage. As they feed, they create silk webbing that sticks food particles together, contaminating the product. This webbing, along with droppings and shed skin, can ruin large amounts of stored food.
Adult mill moths are small, usually about one-fourth to three-eighths of an inch in length, with a wingspan of five-eighths to three-fourths of an inch. They have a black zigzag pattern across the wings, which are gray. Their larvae have a pinkish or greenish tinge (depending on food eaten) with a brown head.
Mill moth larvae pupate in a silken cocoon. They often spin webbing as they feed, which can clump food products together and make them unusable.
Signs of a mill moth problem include webbing in stored grains, flour, or pet food, as well as visible larvae crawling in or around packaging. Adult moths may also be seen flying near food storage areas. These moths are most active at night and are attracted to lights.
Mill moths thrive in warm, dark environments where dry food is stored. This includes grain silos, food processing plants, pantries, and warehouses. They lay their eggs directly in or near food sources, making early detection difficult. Adults tend to rest during the day and fly at dusk.
These moths prefer flour, but will feed on other commodities. Once they find a food source, the larvae can multiply quickly.
The life cycle of a mill moth includes four stages: egg, larva, pupa, and adult. Females can lay hundreds of eggs at once, which hatch in just a few days. Larvae feed and grow over several weeks before spinning cocoons to pupate. After pupation, adults emerge to start the cycle again. The full adult lifespan usually takes up to two weeks.
Mill moth damage can lead to wasted products and production shutdowns in commercial settings. In homes, it may result in throwing away large amounts of pantry items. The biggest threat is often economic, especially for businesses storing bulk grains or flour.
Mill moths can be hard to get rid of, especially in large spaces or where food is stored in bulk. To tackle infestation and help prevent it from recurring, it’s best to work with pest control technicians like Presto-X to inspect and treat the affected areas. They can help find the source and recommend next steps.
If you’ve spotted signs of mill moths or are dealing with other pest problems in your home or business, our technicians are ready to help. We’ll inspect your space, target the problem areas, and work with you to help reduce the chance of them returning.
“Pantry moth” is not a specific species, but a generic term for moths that eat grains. So a mill moth (Mediterranean flour moth) could be considered a type of pantry moth.
These moths often enter through contaminated food products or packaging. In commercial settings, they may also come from nearby grain or flour storage areas.
Look for webbing, clumped food, or small larvae in dry goods. You might also see adult moths flying near food storage areas.
It depends on the size of the problem and how quickly it’s found. In most cases, professional help is needed to fully address the issue and reduce the chance of it returning.
They can enter through packaged food, especially if it has been stored for a while. Small openings around windows or doors may also allow them in.