Several Mussidia species occur in West and East Africa, but only the ear-borer, Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae), has attained economic pest status in West Africa. During recent surveys in Kenya several parasitoid species were recovered from Mussidia species, including the egg parasitoid, Trichogrammatoidea sp. nr lutea Girault (Hymenoptera: Trichogrammatoidea). This parasitoid species is considered a potential biocontrol agent for M. nigrivenella in West Africa and development of a successful rearing system for its host, M. fiorri, will enable the mass production of this natural enemy species. The suitability of five artificial diets for the development of M. fiorii as well as optimum rearing conditions were evaluated in the laboratory. The effect of temperature and humidity on the development of M. fiorii was also studied. Mussidia fiorii successfully developed on maize leaf-, maize seed- and Canavalia ensiformes seed-based diets. The lower developmental thresholds for the egg, larvae, pupae, and egg to adult were 12.8 ± 0.25 °C, 14.4 ± 0.27 °C, 11.0 ± 0.03 °C and 13.5 ± 0.21 °C, respectively, while the thermal constants were 82.0 ± 1.61, 384.6 ± 9.4,144.9 ± 6.8 and 588.2 ± 10.8 degree-days, respectively. Information on dietary and thermal requirements will be used to optimize mass production of the host and natural enemies.