Sampling Tribolium castaneum and Tribolium confusum in flour mill rollstands

► Tribolium populations were sampled inside rollstands in three flour mills. ► Tribolium castaneum was more common than Tribolium confusum. ► There was 16-51% of the beetles in areas in the rollstand that were easy to clean. ► Middling rollstands had higher infestations than the break rollstands. ► The number of beetles inside rollstands were not correlated to beetles caught in traps.