Two polyclonal antibodies (Pab) were developed for the detection of Tribolium castaneum, which is a stored product pest of medical and economical importance. Selected Pab anti- T. castaneumK51 showed low cross-reactivity to other stored product arthropods but revealed high reactivity to T. destructor, T. confusum, and partly to Tenebrio molitor. PTA-ELISA was used to detect adults, larva, and feces of T. castaneum in artificially contaminated grain samples. Calibration methods were applied to determine detection limits for each type of contaminants. Anti- T.castaneumK51 enabled detection of T. castaneum in grain samples; detection limits reached 60 and 640 individuals/kg of grain for larvae and adults, respectively, and 4 mg of feces/kg of grain. After recalculation, the detection limit for feces enables detection of 30 larvae after 5 days of feeding in optimal conditions. The main advantage of the developed assay is traceability of T. castaneum contamination, especially when the adults and larvae are removed from contaminated material, based on the detection of feces that persist in the grain.