The efficiency of the Psyttalia concolor (Szepligeti) [long dash] Ceratitis capitata (Wiedemann) mass-rearing system was investigated. A series of experimental parameters were fixed in order to reproduce in a small-scale, the mass-rearing conditions. Four different parasitization time exposure values were set to study the impacts of these parameters on the parasitization levels and on the parasitoid fitness. Larvae superparasitized with two eggs seemed to represent the most efficient strategy for parasitoid development, wehreas the clutch of 4 or more eggs resulted in a disadvantage for both the host and the parasitoid. Egg distribution patterns were analyzed and further justified with the Poisson distribution. A random egg distribution seemed the strategy adopted by the parasitoid during the 20 minutes host-parasitoid exposure time only. The significances of such kind of egg distribution are discussed. Techniques; Care in captivity; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts Ceratitis capitata (Tephritidae); Hymenopteran parasites; Psyttalia concolor; Parasite mass rearing system efficiency related to host exposure time Psyttalia concolor (Braconidae); Rearing techniques; Dipteran hosts; Ceratitis capitata; Parasite mass rearing system efficiency related to host exposure time none