Meal moth (Ephestia kuehniella)

Size:

• Moth: 10 to 14 mm body length
• Wingspan: 20 to 25 mm
• Larvae: up to 15 mm

Look:

• Forewings grey to silver-grey with a jagged zigzag pattern
• Hindwings lighter and slightly transparent
• Body stretched, hairy
• Caterpillars whitish to pink, with a dark head

Way of life:

• Moth is nocturnal and avoids light.
• The female lays up to 200 eggs directly on the food.
• Larvae form webs in which they pupate.
• Development from egg to butterfly depends on temperature and humidity

Way of life:

• Egg laying on flour, grain, muesli, animal feed or baking ingredients
• Development in 30 to 60 days
• Up to 4 generations per year under ideal conditions
• No overwintering outdoors, year-round propagation in heated buildings

Infestation sites:

• Flour, semolina, muesli, rice, pasta, breadcrumbs
• Grain products, feed grain, bird food
• Both packaged and loose goods are affected.
• Infestation in storage rooms, kitchens, pantries, bakeries

Nutrition:

• The larvae feed on starchy dry products.
• They infect both human and animal food products
• Excrement, spider webs and larval skins contaminate the products.
• Adult animals no longer eat.

Behave:

• The butterfly rarely flies directly into view, hiding during the day.
• Larvae will even crawl out of packaging when food is scarce.
• Webs visible in infested material
• Rapid spread at warm temperatures and high humidity

Economic damage:

• Rejection and destruction of entire batches in industry or trade
• Production losses due to cleaning and remediation measures
• Damage to reputation from repeated occurrences in the catering or retail sector

Hygiene risks:

• Perforated packaging
• Contamination from feces, webs, shed skins and dead animals
• The smell and taste of the products change

Infestation dynamics:

• Moths are harmless, larvae cause the damage.
• Undetected infestations can spread massively within a few weeks.
• Heat generated by mass infestation promotes further development
• Repeated infestation by overlooked pupae or undetected sources of contamination

Disease transmission:

• Transport of microorganisms
• Concentration of foods

Storage hygiene:

• Store supplies in a cool, dry place and tightly sealed.
• Store supplies in well-sealed, airtight containers.
• Completely empty and clean old stock before refilling.

Monitoring:

• Pheromone traps for the early detection of moths
• Visual inspections for webs, larvae or crawling animals
• Temperature and humidity measurement in grain piles
• Check packaging for holes or dust residue.

Behave:

• Do not store loose supplies in open bags.
• Do not dispose of infested goods with waste, but destroy them in plastic bags.