the importance of the protein ingestion during the adult stage on the mating success of males of ceratitis capitata wiedemann was evaluated in experiments of laboratory and field cage. in laboratory, the effects of protein ingestion during the first four or 12 days of the male adult life was assessed by the following parameters: mating success (capacity of being chosen by the female) and the number of males that give out pheromonal signals. some experiments of mating success had been carried through with males in different ratios. in these tests, the number of males which had ingested protein (an unique male) was remained constant and the number of males fed without protein was gradually increased from 1:1 to 1:5. in the field cages, the mating success experiments were done using a 1:1 ratio. the results showed that the protein ingestion in the first four days of life did not influence any of the analyzed parameters. when the period of ingestion of protein was extended to 12 days, protein-fed males fed produced more pheromonal signals and had a higher mating success when at a 1:1 ratio in laboratory and field cage assays. in laboratory, females randomly chose males in any other tested ratio (1:2, 1:3, 1:4 and 1:5), indicating that the female may lose the perception to identify the male who ingested protein in the first 12 days.