Identification
The Angoumois Grain Moth is a small, pale yellowish-brown moth with a wingspan of approximately 10–16 mm. Its forewings are narrow and pointed, while the hindwings have long, hair-like fringes. The moth has a distinctive head with large, dark eyes and long, thread-like antennae. Larvae are small, white, and slightly curved, measuring up to 5 mm in length.
Lifecycle & Reproduction
This species undergoes complete metamorphosis, consisting of egg, larva, pupa, and adult stages. Females lay up to 300 eggs directly on whole grains or inside grain storage areas. Eggs hatch in 4–8 days, and larvae burrow into grains, feeding internally for 2–3 weeks. Pupation occurs inside the grain kernel, lasting 1–3 weeks before adults emerge. The entire lifecycle takes about 25–40 days, allowing for multiple generations per year in warm conditions.
Habits, Diet & Behavior
Angoumois Grain Moths primarily infest whole grains such as wheat, corn, rice, and barley. Unlike many pantry moths, their larvae develop inside the grain kernel rather than on the surface. Adults are weak fliers and tend to remain near infested areas. They are most active during warm seasons and can rapidly spread in storage facilities and grain processing plants.
Where You’ll Find Them / Typical Locations
- Grain storage facilities and silos
- Pantries containing whole grains
- Farms and agricultural warehouses
- Food processing plants handling raw grains
- Grain transportation containers
Threats & Danger
The Angoumois Grain Moth poses a significant threat to stored grain by reducing its quality, weight, and germination viability. Infested grains become weakened, often leading to secondary infestations by other pests. The presence of larvae and their excrement contaminates food, making it unsuitable for human or animal consumption. Infestations result in substantial economic losses in grain production and storage industries.
Prevention
- Store grains in airtight, sealed containers.
- Inspect newly purchased grains for signs of infestation before storage.
- Keep storage areas dry and well-ventilated to reduce humidity.
- Use pheromone traps to monitor moth activity.
- Regularly rotate grain stock to prevent long-term storage infestations.
Signs of Infestation
- Presence of small, pale brown moths flying near stored grains.
- Hollowed-out or damaged grains with internal larvae.
- Fine powder or frass (insect excrement) accumulating in grain storage.
- Increased grain dust and mold growth due to larval feeding.
- Clumping of grains caused by webbing from larval activity.
How to Get Rid of It
- Dispose of infested grains: Seal and discard contaminated products.
- Freeze affected grains: Store grains at 0°F (-18°C) for at least a week to kill eggs and larvae.
- Deep clean storage areas: Vacuum shelves and wipe with vinegar or soapy water.
- Use pheromone traps: These help monitor and capture adult moths.
- Heat treatment: Drying grains at 120°F (49°C) for several hours can eliminate infestations.
- Consult professional pest control: For widespread or persistent infestations, expert treatment may be necessary.