The species which we refer to as flour beetles are similar to each other by occurring in flour and other cereals. These beetles are flat, elongated, shiny beetles with almost parallel sides. The prothorax is quite broad. The largest of the species are black, the smallest maroon. These beetles belong to the family of darkling beetles (Tenebrionidae). The dark flour beetle and the two kinds of confused flour beetle belong to the same genus, Tribolium. Systematists have had difficulties sorting the individual species according to their statuses within the genus Tribolium. This means that all the species of this genus are listed as quarantine insects.