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Pest SolutionsPESTS + WEEDSUSING PESTICIDES OR HERBICIDES?
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Insects in Stored Food
Many species
Updated Dec 19, 2023
Make a Positive Identification
There are several species of insects that infest stored food. Control methods are the same for all of them.
Meal Moth
Species: Meal Moth
"Plodia interpunctella" by Gilles San Martin is licensed under CC BY-SA 2.0.
Meal moths (Plodia interpunctella) commonly infest a wide variety of stored foods. Adult meal moths are 1/3 to 2/5 inches long with a wingspan of about 3/5 of an inch. Their wings are held flat along the length of the body as shown in the photo. The front third of their wings is whitish-gray. The rest is coppery brown.
Species: Meal Moth
"Plodia interpunctella larva" by reginamariek is licensed under CC BY-NC 2.0.
Meal moth larvae feed on and damage stored foods such as grains. They are about 1/2-inch long when fully grown. Their color is white or sometimes pinkish or greenish. Meal moth larvae have three pairs of legs close to the head, as shown in the photo. They also have leg-like structures farther down the abdomen.
Species: Meal Moth
Mohammed El Damir, Bugwood.org
Meal moth larvae create a web as they grow and crawl around. The photo shows Indian food infested with meal-moth eggs, larvae, webbing, and adults.
Beetles
Species: Flour Beetle
Peggy Greb, USDA Agricultural Research Service, Bugwood.org
Confused flour beetle (Tribolium confusum) and red flour beetle (Tribolium castaneum) are similar species. Adult beetles have shiny, flattened, reddish-brown bodies. They are about 1/7-inch long. Adult beetles of these species damage stored food.
Species: Flour Beetle
© Ken Gray Insect Image Collection
Small larvae are slender, cylindrical, and wiry in appearance. They are about 3/16-inch long and white, tinged with yellow. In general, beetle larvae are either legless or have three pairs of legs close to the head as shown in the photo. Beetle larvae damage stored food.
Species: Cigarette Beetle
Brian Little, The University of Georgia, Bugwood.org
Cigarette beetles (Lasioderma serricorne) and drugstore beetles (Stegobium paniceum) are similar species. Adult beetles are 1/8-inch long, oval-shaped, and light brown. Larvae and adults of both species damage stored food.
Other Insects in Stored Food
Species: Angoumois Grain Moth
Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org
Angoumois grain moth (Sitotroga cerealella) is another pest in stored whole grains such as rice, wheat berries, and corn. The moths bore into intact seeds and feed inside the seed covering.
Species: Mediterranean Flour Moth
© Ken Gray Insect Image Collection
Mediterranean flour moth (Anagasta kuehniella) prefers to feed on flour meal and whole cereal grains.
Species: Bean Weevil
LiuSol, iStock
Bean weevils (Acanthoscelides obtectus and Bruchus pisorum) damage bean crops in the field. They also feed on and damage stored beans.
Species: Grain Mite
© Ken Gray Insect Image Collection
Tiny mites also infest stored food. They occur in moist or damp conditions. Watch for piles of brownish dust on shelving, around flour sacks, or on the surface of stored foods.
Species: Carpet & Hide Beetles
Photo credits
Left:
Gary Alpert, Harvard University, Bugwood.org
Right:
Whitney Cranshaw, Colorado State University, Bugwood.org
Carpet beetle larvae are covered with tufts of hair as shown in the photo (left). These larvae damage many stored foods.
Carpet beetles and hide beetles are similar species. Both are about 1/10-inch long. Carpet beetles are mottled white, brown, and dark yellow as shown in the photo (right). Hide beetles are brown.
Insects in Stored Food Benefits
- Insects in stored food are regarded as pests. They don’t have any benefit for people or the environment.
Insects in Stored Food Risks
- Insects in stored food are not known to spread any known diseases, parasites, or pathogens.
- They can contaminate stored food with hairs, droppings, webbing, and secretions.
- Hairs from some beetles can irritate your mouth, throat, and stomach when ingested.
- Insects in food spread microbes that rot food, especially in warm, humid conditions.
Risk Card
Does it cause harm?
Adults & Children
Low
Property
Some
Ruin stored food
Pets
None
Annoyance
Some
Dispose of infested food and clean area
Environment
None
Action Recommended
Take Action
Take action for insects in stored food. The sooner you take action, the easier the problem will be to address.
Do I need to take action?
Yes. They ruin stored food.
What if I do nothing?
Pantry pests won’t go away on their own. They will ruin more stored food if you don’t take action.
Prevent Insects in Stored Foods
Signe Danler, Oregon State University
Inspect Food Packages
- Inspect packages or bulk products before buying. Don’t buy broken or damaged packages of food. They are more likely to become infested.
- Check the freshness packaging date.
- When buying large quantities of whole grains or beans, freeze them for at least four days to kill any eggs or insects that may be present.
Signe Danler, Oregon State University
Follow These Storage Tips
- Store food that attracts pantry pests in glass, metal, or heavy plastic containers with tight-fitting lids. Don’t store food items in plastic or paper bags, or cardboard boxes.
- Don’t store large quantities of bulk foods for longer than 2 months unless they are kept in the freezer.
- Store seldom-used grains and spices in a freezer.
- Don’t mix old and new food together. If the old food is infested, the pest will invade the new food. Use the oldest foods first.
Photographer, iStock
Clean Food-Storage Areas Regularly
- Clean shelves, bins, and other food-storage areas regularly.
- Clean up spills and crumbs in food-storage areas. Spilled food attracts insect pests.
- Vacuum cracks and crevices to get rid of eggs, pupae, and spilled grains.
- Clean the surfaces of food-storage areas with hot soapy water. Let the area dry before replacing items.
- Wash old containers before filling them with new food.
- Check and clean areas where pet food and birdseed are stored.
- Cleaning up stored food messes also minimizes food sources for mice and rats.
Whitney Cranshaw, Colorado State University, Bugwood.org
Monitor with Pheromone Traps
- Watch for small moths or beetles crawling or flying around your kitchen. Look for the food source of these pests and remove it immediately.
- Use pheromone traps (see section 4) to monitor for the presence of pantry pests.
- If you see pests more than 3 weeks after an infestation was cleaned up, there is still an infested food source.
- Pantry pests can breed in rodent baits. Be sure to check frequently and discard infested baits.
Solutions for Insects in Stored Food
- If you find small moths flying or beetles crawling around your kitchen, look for infested stored food. Remove the infested food.
- By the time you notice the insects, they have likely spread to multiple food packages.
- Discard infested foods and clean the area thoroughly.
- Use pheromone traps to catch and monitor for insect activity.
NEED HELP?
Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
Jump to
| Method | Does it work? | Is it safe? | Recommendation |
|---|---|---|---|
A Clean Up Insect Messes |
Very effective |
Low risk |
Recommended |
B Pheromone Traps |
Effective |
Low risk |
Recommended |
C Insecticides for Indoor Use |
Does not work |
High risk |
Not Recommended |
|
D If Using Insecticides, Protect Yourself & Minimize Risks
|
A
Clean Up Insect Messes
Non-Chemical Method
Signe Danler, Oregon State University
Clean Up Insect Messes
Recommended
Cleaning up pest infestations in the pantry is a required step to get rid of the problem.
| Does it work? | Very effective |
| How much effort? | Moderate effort |
| What's the risk? | Low risk |
| Possible risk of exposure or harm from chemicals | NONE |
Signe Danler, Oregon State University
Weston Miller, Oregon State University
Signe Danler, Oregon State University
Signe Danler, Oregon State University
Signe Danler, Oregon State University
Stored food products infested by insects should be considered ruined and thrown away. However, if the infestation is minor, the food can be safely salvaged. Sift the insects out. Cook the food for at least ½ hour at 140℉ or higher. The heat will kill insect eggs, larvae, and adults. Freezing insect-infested food for at least 3–4 days will also kill insects. Eating insect-infested food that’s been cooked or frozen isn’t known to cause illness or harm.
B
Pheromone Traps
Non-Chemical Method
Weston Miller, Oregon State University
Pheromone Traps
Recommended
Use pheromone traps to monitor and trap meal moths and food pantry beetles.
| Does it work? | Effective |
| How much effort? | Low effort |
| What's the risk? | Low risk Pheromone traps use natural scents to attract insects and sticky glue to capture them. They don’t include pesticide ingredients. |
| Possible risk of exposure or harm from chemicals | NONE |
Weston Miller, Oregon State University
Whitney Cranshaw, Colorado State University, Bugwood.org
More About Pheromone Traps
- Pantry pests can live for many weeks without food. Use pheromone traps to detect pests that may still be present after you clean up infested food.
- Place the traps near a previous infestation. Check the traps weekly. Most traps remain effective for about three months.
- If you find moths or beetles in traps, inspect food packages again for an infestation. Dispose of infested food and clean up the mess as needed.
C
Insecticides for Indoor Use
Chemical Method: Use with caution
Weston Miller, Oregon State University
Insecticides for Indoor Use
Not Recommended
Insecticides (insect killers) are not recommended for controlling insects in food.
| Does it work? | Does not work They don’t kill insects inside food packages. Food packaging protects the insects from contact with insecticides. |
| How much effort? | Moderate effort |
| What's the risk? | High risk Spraying pesticides on or near food can contaminate your food and cause harm to you and your family. |
| Possible risk of exposure or harm from chemicals | El uso de insecticidas conlleva cierto grado de riesgo. El riesgo más bajo se presenta con el uso de métodos alternativos. You may be exposed to an insecticide if you:
Follow directions closely to reduce risk. |
If you’ve already applied an insecticide for food pantry pests:
- Throw away any food that has come in contact with insecticides.
- Thoroughly wash cupboards, containers, and dishes that have come in contact with insecticides.
If Using Insecticides, Protect Yourself & Minimize Risks
Chemical Method: Use with Caution
The Label is the Law
ALWAYS read the label before using insecticide products. The label is a legal document that provides information on how to safely use the insecticide. This helps avoid harm to human health and the environment. Using an insecticide in off-label ways is illegal. It can result in legal enforcement actions.
READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.
- Labels are different for every product and they often change over time.
- Use a magnifying glass for small print.
- Pay attention to CAUTION, WARNING, and DANGER statements.
- Pay attention to the PRECAUTIONARY STATEMENTS.
- The law states you must read and follow insecticide instructions.
Protect Yourself
Eye, skin & lung irritants
- Wear gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
- Avoid contact with eyes, skin, or clothing.
- Wash hands after mixing or applying, and before eating or smoking.
Protect Children & Pets
Keep out of the reach of children.
- Keep children and pets away from the application area.
- Remove toys and pet dishes from the area before applying insecticides. Wait until spray has dried or dust has settled.
Storage & Disposal
- Store out of the reach of children and pets.
- Store in a cool and dry place.
- Never pour down any drain.
- If you mix too much, apply it rather than storing it.
- Don’t put pesticide containers in the trash unless instructed by the label.
- Take unused insecticides to a hazardous waste facility.
Call 1-800-CLEANUP (1-800-253-2687) to find out where to dispose of pesticides.
For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call 503-234-3000, email or visit Metro’s website
More about:
About Using Pesticides on School Grounds in Oregon
If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management (Oregon Department of Agriculture).
NEED HELP?
The National Pesticide Information Center (NPIC) can answer questions about pest control chemicals.
1-800-858-7378 or npic@ace.orst.edu
Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon and other states can suggest other methods.
Content provided by writer Signe Danler. Pesticide safety information edited by Kaci Buhl.
Reviewed by OSU Department of Horticulture.
Insects in Stored Food References
Pantry pests: Insects found in stored food
University of Minnesota Extension
Pantry Pests
University of California IPM
Pantry Pest Guide
OSU Extension Service
Variegated Carpet Beetle
OSU Extension Service