Diachasmimorpha longicaudata is the most widely used braconid in biological control programs of fruit flies around the world. The objective of this study was to investigate the influence of different parasitoid-host ratios on D. longicaudata parasitism of Ceratitis capitata and Anastrepah fraterculus. Larvae of these fruit fly species were exposed to 5 different parasitoid-host ratios (4:1, 2:1, 1:1, 1:2 and 1:4). Subsequently, the numbers of oviposition scars and of parasitoid larvae per host were evaluated in the pupal stage. In both tephritid species, a larger number of scars and parasitoid larvae were observed at the 4:1 and 2:1 ratios. Results suggest that females of D. longicaudata can superparasitize both hosts. The differences between the tested parasitoid-host ratios suggest that there is an optimum parasitoid-host ratio for multiplying this natural enemy. These results are important for improving mass rearing programs of D. longicaudata.