Fluorescent dyed melamine copolymer resins were evaluated to determine their effectiveness for marking adult Rhyzopertha dominica to be used in release-recapture experiments. Pigments were retained very well, and marked individuals were easily identified under longwave ultraviolet light up to 21 d after treatment. Little pigment was transferred between individuals during mating or other contact within a bulk of wheat. Treatment with fluorescent pigment did not reduce fecundity or prevent flight activity.