ABSTRACT Campoletis flavicincta (Ashmead) (Hym.: Ichneumonidae) is a solitary larval endoparasitoid with potential to control Spodoptera frugiperda (J.E. Smith) (Lep.: Noctuidae). The effect of female parasitoid age (days after emergence) and number of days before receipt of the host larvae (1, 2, 3, 4 and 5 days after emergence of C. flavicincta) on progeny production and parasitism rate were studied. Twenty-four larvae of S. frugiperda were supplied daily for each parasitoid pair until female death. The total number of males produced was similar regardless of when host larvae were supplied but daily male production decreased with female age (p < 0.05). The daily and total number of females produced during the lifespan of female C. flavicincta and the sex ratio were higher when host supply began three to four days after the emergence of adult parasitoids (p < 0.05) than in the other treatments. The daily production of females and the sex ratio (females/females + males) increased with female age to a maximum at 8.5 and 9.3 days and then decreased (p < 0.05). Parasitism rate was already high (< 60%) at the beginning of host supply, reached a peak for six-day old females and declined afterwards. Mortality of S. frugiperda larvae and viability of C. flavicinctapupae were not affected by female age and delay in supplying host larvae. Longevity of C. flavicincta females receiving hosts at a younger age was shorter (p < 0.05). It is recommended to start supplying larvae of S. frugiperda after three to four days of emergence of C. flavicincta females to maximise female production of this parasitoid.