Although functional response and mutual interference studies may be of great importance to augmentative biological control projects focussed on pests of economic importance, such studies have traditionally been overlooked in mass rearing projects of natural enemies. In this study, we aimed to explore both interactions in Utetes anastrephae (Viereck), a native parasitoid commonly associated with Anastrepha obliqua (Macquart), a major fruit fly pest of Spondias spp. and Mangifera indica L. in the Americas, for mass rearing purposes. The functional response of U. anastrephae on A. obliqua larvae fit a type II model according to Holling's disc equation, with an instantaneous rate of discovery (a’) of 0.470 and a handling time (Th) of 0.099. The effects of mutual interference were more severe at high parasitoid densities due to the higher frequency of interactions. An increasing number of foraging females resulted in an increasing number of oviposition scars and immature parasitoids per pupa without significant differences in the total number of attacked larvae. Superparasitism at high densities of foraging females had a negative effect on adult emergence, was associated with a female-biased sex ratio, and had no effect on survival or flight ability parameters. Strategies for optimizing the mass rearing of this parasitoid species are outlined.