Red and confused flour beetles are non-native insect pests in the US that originated from Australia and Africa, respectively. These two pests can be found in most areas throughout the country, but red flour beetles tend to be more common household pests in the south, while similar looking confused flour beetles tend to be slightly more common in homes located in the north. Both of these species are found infesting homes throughout the year in warm southern states, but red flour beetles can maintain indoor infestations during the winter season in the northern states, especially within heated structures. Interestingly, these two beetle pest species often share the same habitat where they compete for resources, and their dual presence within a home is not unheard of in the US. Both red and confused flour beetles infest pantries, cupboards and other locations where grain-based foods are stored, and they are considered the two most significant insect pests of stored foods in the US.

Unlike most insect pests of stored food, adults as well as larvae of the adult red and confused flour beetle species invade stored food kept in containers and packages, and they are often found nestled into narrow cracks on walls located near exposed food and spilled beverages. While neither one of these insect pests feed on sound and undamaged grain, they are both known for invading containers and packages in large numbers where they feed and contaminate a number of common grain-based foods. Some of the food items favored by red and confused flour beetles include crackers, beans, spices, pasta, cake mix, bagged pet food, dried plants, chocolate, nuts, and seeds. These pests are particularly attracted to grains that have absorbed moisture, and contaminated grains can be recognized for having an irregular greyish tint.

Foods that have become contaminated by these pests are also apt to develop mold growth, and all foods that have become compromised by red and confused flour beetles should be sealed in an airtight container or bag before being discarded. These pests also establish harborages within wall cracks in areas outside of kitchens where grain-based foods are not present, and they are often found in clusters on indoor surfaces, cushions and fabrics that contain small amounts of spices, grain residue and plant matter. Both red and confused flour beetle adults are relatively small at only ⅛ of an inch in length, and they appear nearly identical with a reddish-brown colored exterior. Their presence can also be recognized by an unpleasant odor emanating from their aggregation sites.

Have you ever taken notice of insect pest damage to stored foods?