Flour beetles are common household insect pests of stored food products, particularly starchy foods, like cereals, pasta, pet food, beans, spices, chocolate, nuts, seeds, and obviously, flour. Flour beetles usually infest homes after residents unknowingly transport the insect pests into their homes within infested food items purchased at supermarkets. Flour beetles often establish infestations within food processing plants and food storage warehouses, which is how the pests wind up within packaged food products. This makes flour beetles a significant problem for food companies as well as residents, but these insect pests can invade homes from the natural environment on occasion as well. The two most significant flour beetle pest species in the US include confused and red flour beetles, and these two species are considered the most important and common insect pests of stored food products in the US.

The red flour beetle is most common in the southern states due to this species’ preference for warm conditions, but they are common in the northeast as well where they can survive winters by securing shelter within heated homes. The confused flour beetle is more tolerant of cooler conditions, making this species most abundant in the northern states. Maintaining sanitary cupboards and pantries and making sure that all food containers are tightly sealed can help to prevent flour beetle infestations. Some homeowners who fall victim to flour beetle infestations kill the pests by placing their infested food products into the freezer for at least a week in order to prevent live flour beetles from emerging from the garbage and spreading around a home. Homeowners may also use store-bought aerosol insecticides containing cyfluthrin, permethrin, resmethrin, or tetramethrin in order to exterminate flour beetles hiding within cracks, crevices and other hiding places around a home. However, heavy infestations usually need to be addressed by a licensed pest control professional.

Have you ever found flour beetles infesting your store-bought food items?