Up to 5/8 inch in length; wingspan less than 1 inch.
The front wings are a pale gray with transverse black wavy bars.
The female deposits her eggs in any suitable food material and usually fastens them to the food particles. The young larva spins silken tubes constantly and spends its time in these tubes feeding. The silk causes balls of form, which can clog machinery in flour mills, necessitating downtime to clean the machines. The larvae may pupate in a cocoon within the flour or on the surface of the flour. They may also pupate in some crack or crevice either within or without a cocoon, often migrating from the food source in search of a pupation site. These larvae are therefore commonly seen significant distances from the breeding source. The life cycle from egg to adult can be completed in four to six weeks in heated buildings and six or more generations per year can occur. The adult moths are active fliers and fly in a very rapid zigzag fashion.
This moth is a significant pest of flour and is a serious pest of mills and warehouses. It also infests nuts, chocolate, seeds, beans, biscuits, dried fruits and stored foods of many kinds. They have even been found feeding in brood combs of honeybee nests. Mediterranean flour moths are not uncommon in supermarkets, drug stores and convenience stores where it can be found infesting chocolate, birdseed and pet foods. It may also be found in restaurants, homes and other end-users of food products.
The control of any stored product pest involves many steps, primary of which is discovery of infested food items or other sources of infestation (e.g., food spillage accumulation). All dried food products need to be inspected for signs of infestation, including cereals, packaged dried foods (e.g., food bars and chocolate), nuts and pet foods. Keep in mind that infested items may not always be stored in the kitchen. Items containing or made of vegetative products may be stored in any room of a house. A common source may be bags of bird seed or pet foods stored in the garage or basement. A pest management professional can be helpful in finding difficult infestation sources. Also consider the following to prevent an infestation:
• Discard infested foods in outdoor trash. Infested decorations (flowers, wreaths, etc.) should also be discarded.
• Freeze suspect foods at zero degrees Fahrenheit for six days.
• Clean cabinets and shelves where infested foods are stored by vacuuming and by using soap and water.
• Inspect the home to find and remove as many cocoons as possible that may be located in corners, behind pictures, etc.
• Store all dried food goods, including dried pet foods and birdseed, in a glass or plastic container with a tight lid. If beetles are in that food product then the infestation will be contained and not spread to other foods.
• Consider storing cereals and similar foods in the refrigerator to limit stored product pest problems.
• Consume older food products prior to newer purchases of the same food. Products purchased in larger quantities (e.g., from a wholesale food warehouse) are more likely to become an infestation source if these are stored for long periods of time – especially if they are not stored in containers with tight-fitting lids.