Type of pest: Secondary pest.
Distribution: Worldwide, intolerance of temperate conditions.
This moth with its origin in India, was found for the first time in 1877 in a package of U.S. wheat in Europe. Since then the Mediterranean flour moth has spread throughout Europe.
Identification: Adults have short labial palps and are curved upwards. The forewing (7-14 mm) is gray with darker markings. E. kuehniella is larger and more clearly marked than the E. elutella. Larvae is 15-22 mm and white and pink in color with black spots (at the basis of the hairs), with the rim of the abdominal spiracles evenly thickened.
Similar species: Hofmannophila, Corcyra, and distinguishing from Cadra is only reliable by examination of genitalia.
Life cycle: Optimal conditions are 40 days at 25 ºC, 75 % r.h. The E. kuehniella lays its eggs in the flour, and the larvae start to eat from the meal until they are mature. Then they find a quiet spot to pupate. The larvae are external feeders, producing silk webbing. Adults are short-lived, do not feed on a commodity and can fly. Below 13 º C, the development of the E. kuehniella virtually stops.
Commodities infested: Dried material of plant origin e.g. cereal products, oilseeds, cocoa, chocolate, spices, nuts, dried fruit, processed foods. The larvae of the E. kuehniella infest flour with their droppings and make it unfit for consumption. As larvae eat they leave a silky, sticky thread behind making the flour clump. Rooms where flour is stored and produced should be kept clean, as often moths live in spilled residue and contaminate other products from there. Walls and floors should therefore be smooth and seamless. Moths often live in dirty filters and vacuum cleaners, so that good cleaning and regular monitoring is also very important. It often happens that machines get clogged and need to be dismantled.
Incoming goods should be monitored closely for the presence of moths, and preventive treatment can prevent infestation. Moths breed faster when a space is humid and warmer.
Treatment: Controlled Atmosphere for infestation in product
Treatment: Heat Treatment for infestation in buildings