Indian meal moth

Plodia interpunctella

1. Identification

• Common name: Indianmeal moth
• Scientific name: Plodia interpunctella Hübner
• Order: Lepidoptera
• Family: Pyralidae

2. Pest description

• Caterpillars whitish to pinkish in colour, with a brown head; reaching about 12–15 mm.
• Adults with bicoloured forewings: greyish basal half and coppery distal half; greyish hindwings.
• Cosmopolitan species, one of the main pests of stored products.
• Caterpillars feed on cereals, flours, dried fruits and nuts, animal feed, seeds and various food products.
• They produce webbing and food clusters, contaminating the products.

3. Main hosts

• Flours and cereals.
• Rice, maize, wheat, oats.
• Dried fruits and nuts (almond, walnut, peanut).
• Animal feed and various seeds.
• Plant-based food products, packaged or in bulk.

4. Symptoms and damage

• Presence of webbing and food clumps.
• Contamination by excrement and insect fragments.
• Holes in packaging, especially cardboard or thin plastic.
• Unpleasant odour and deterioration of product quality.
• Significant economic losses in warehouses, industries and domestic pantries.

5. Biological cycle

• Eggs laid directly on the food or nearby.
• Caterpillars develop inside or on the surface of stored products.
• Pupation occurs in cracks, walls, shelves or in the food itself.
• Adults emerge and quickly restart the cycle.
• Several generations per year, favoured by high temperatures and food availability.

6. Monitoring

• Pheromone traps to capture males.
• Visual inspection of stored foods and packaging.
• Checking for webbing, lumps and caterpillar movement.
• Regular monitoring in warehouses, kitchens and storage areas.

7. Management measures

• Cultural: thorough cleaning of shelves, removal of infested products, storage in airtight containers.
• Preventive: inspection of products on arrival; maintenance of hygiene conditions; reduction of exposed food sources.
• Biological: use of specific parasitoids in industrial settings (where applicable).
• Integrated Protection: use of pheromone traps; authorized treatments in structures when necessary; integration of cultural and preventive measures.

Bibliographic references

• EPPO Global Database – Plodia interpunctella.
• CABI – Invasive Species Compendium – Plodia interpunctella.
• Hill, D. S. (1990). Pests of Stored Products and Their Control. CRC Press.
• Hagstrum, D. W. et al. (2012). Atlas of Stored-Product Insects and Mites. AACC International.