Brief SummaryRead full entry
Mediterranean flour moth caterpillars are a common pest, infesting grain, flour, baked goods and cereal products. They cause damage by eating especially the germ and bran from grain, and leaving frass, webbing, and body parts in stored dried foods. They are found in households as well as mills, warehouses, and processing plants. If left uncontrolled, the species may reach extreme population densities in suitable locations, such as mills, and the silken webs produced by the caterpillars may even impair the functioning of flour sieves and other machinery (Canadian Grains Commission 2009; Wikipedia 2011).
The adult moth is small (wingspan between 16-20 mm) with a dark grey zig-zag pattern on the fore wings, and dull grey hind wings, with a grey fringe on the wing margin. The moths are active mostly at dusk and dawn. In rest, it has a characteristic slope to its body position with its forelegs extended, holding its head up higher than the rest of the body. The female moth lays somewhere between 100-200 eggs, often attached to flour or grain particles. These small, white eggs hatch in just a few days. The off-white or pink larvae have a dark head, and two dark spots on each segment. They spin a protective tube in which they feed and grow for about 40 days, reaching a size of up to 12mm. The larva can also rest in diapause for up to a year before pupating if conditions are not favorable. Once they are large enough to pupate, they find a location outside the food source and spin a silk cocoon. Mediterranean flour moths can undergo several generations per year (Canadian Grains Commission 2009; Wikipedia 2011).
As with most grain- or flour-feeding pests the most effective method of control is to adopt basic good sanitary practices. Products already affected should still be thrown away. It is essential to ensure that food storage areas are kept clean and tidy and that no residues are left over. In addition it is imperative that food – especially grain, sugar and flour – is kept in plastic or metal storage containers with tight fitting lids. This will stop flour moths and other pests from getting at their contents. Tiny gaps, even at the rim of Tupperware lids, will allow oviposition (Wikipedia 2011). Another safe, specific and effective option for control is to use pheromone traps, which are easily available for home use. Pheromone traps use a lure that is made from synthesized mimics of the specific sex pheromones that the female Ephestia kuehniella moths emit to attract males when they are ready to breed. The males are attracted into the trap and then get caught by sticky paper, disrupting mating in this species (Ogg 2008).