Comparative studies were conducted in Reunion island on the courtship behaviour of the mediterranean fruit fly, Ceratitis capitata (Wiedemann) and the natal fruit fly, Ceratitis rosa (Karsch). Preliminary observations were also made on another Ceratitis, endemic from the Mascarenes, Ceratitis catoirii Guérin-Mèneville. Preliminary experiments in field cages allowed us to precise the optimal age for mating in local wild populations of C. capitata (9 days-old adults) and C. rosa (13 days-old males, and 13-15 days-old females). Video recordings of close interactions between wild males and females C. capitata showed no significant differences between the durations of male or female activities and mating success. Some video recordings of lab C. rosa and C. catoirii allowed us to precise close interactions between sexes during courtship behaviour in these species. In C. rosa, male courtship display involves fanning but no buzzing or head-rocking. Close interactions are very brief and before assault male throws its mid-legs in the direction of the female. In C. catoirii male courtship appears more similar to medfly's male behaviour, including fanning, buzzing, but no headrocking. Circadian rythm of C. caloirii male calling was studied in lab cages, showing that most activities occur in the morning in this species. The study of circadian rythm of activities of both sexes of C. rosa in field-cages and in a citrus orchard shows that the peak of courtship activities in the end of the afternoon coincides with a peak in egg-laying activity of females. The spatial distribution and structure of leks in C. rosa were studied in a citrus plot at preharvest period. In these conditions, male calling was shown to occur mostly on the underside of fruits.