<p>Competitive interactions between sympatric parasitoid species within the same guild sharing the same host may reveal important coevolutionary traits of species that could potentially be used as biocontrol agents. We studied the competitive interactions between two fruit fly larval parasitoids, <i>Utetes anastrephae</i> (Viereck) (Hymenoptera: Braconidae) and <i>Doryctobracon crawfordi</i> (Viereck) (Hymenoptera: Braconidae), and the pupal parasitoid <i>Coptera haywardi</i> (Ogloblin) (Hymenoptera: Diapriidae), all of which attack the Mexican fruit fly, <i>Anastrepha ludens</i> (Loew) (Diptera: Tephritidae) immatures. We used different proportions of unparasitized/parasitized pupae (60/0, 45/15, 30/30, 15/45, and 0/60) of two ages (three-day-old, eight-day-old), which were previously attacked by one of the larval parasitoids and then exposed to the pupal parasitoid. In accordance with other studies that have shown the superiority of early-acting opiine parasitoids of fruit flies, our results showed that the larval parasitoids had an advantage over the pupal parasitoid: the latter exhibited a significant decrease in offspring emergence as the availability of unparasitized pupae decreased. This contrasts with the results of a previous study showing that <i>C. haywardi</i> can act as a hyperparasitoid of the exotic <i>Diachasmimorpha longicaudata</i> (Ashmead) (Hymenoptera: Braconidae) under similar experimental conditions, which was attributed to the lack of coevolutionary traits between these species. We conclude that the larval parasitoids successfully defended their hosts against possible multiparasitism and minimized the parasitic activity of the invader pupal parasitoid, which provides important information when considering using <i>C. haywardi</i> as a complementary natural enemy for the control of <i>A. ludens</i> populations.</p>