Red flour beetle

(Tribolium castaneum)


The red flour beetle, which belongs to the same family (fam. Tenebrionidae, darkling beetles) as the mealworm beetle, is light red-brown in colour and its body reaches a length of 3 to 4 mm. Female red flour beetles lay their eggs loosely on the affected product. The slim, extremely agile larvae are 6 to 8 mm long and are whitish to yellow-brown. The creatures are thermophilic and not very resistant to cold temperatures.

Longer periods at temperatures of 0 °C are fatal for all stages.

The confused flour beetle (Tribolium confusum), which is very similar in terms of appearance, lifestyle and damage caused, often appears alongside the red flour beetle. Both types are capable of flying, but the red flour beetle flies a lot more.



Flour beetles have a broad diet of plant-based products, such as flour, flour products, pasta, nuts, dried fruit, copra, and much more. Both the larvae and the beetles can cause damage with their feeding activities. Affected flour takes on a very unpleasant odour as a result of the quinone released by the flour beetles, turns pink and can no longer be baked. This is said to have a carcinogenic effect.

Flour beetles are a common pest in mills and commercial bakeries.