According to British statistics, the rust-red flour beetle is that kind of food pest that most frequently is brought to Europe by sea. It has been found in 23% of the consignments while the closely related confused flour beetle has only been seen in less than 1% of the consignments.
In the Nordic countries the frequency is just the opposite. The rust-red flour beetle is a tropical species with slightly higher heat requirements than the confused flour beetle and it belongs in a warm, temperate climate. In addition, the rust-red flour beetle is not as tolerant to cold as the confused flour beetle.