Background Egg parasitoids belonging to the genus Trichogramma (Hymenoptera: Trichogrammatidae) are important natural enemies that have been successfully used in biological control programs and mostly reared on the Mediterranean flour moth, Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae). Host quality is a crucial factor that can determine parasitoid fitness. Main body Laboratory studies were carried out to evaluate the effects of 3 different larval diets CY diet (95% cornmeal + 5% yeast), CBGY diet (53.3% cornmeal + 26.7% wheat bran + 15% glycerine + 5% yeast), and WBGY diet (53.3% wheat flour + 26.7% wheat bran + 15% glycerine + 5% yeast) on some demographic parameters of E. kuehniella. Moreover, the performance of the species Trichogramma evanescens Westwood reared on the E. kuehniella eggs reared on the 3 artificial diets were determined. For the E. kuehniella rearing, the CY diet had a higher fecundity and greater emergence ratios. Nevertheless, CY diet also provided shorter developmental time, greater fecundity, and relatively higher female ratios of subsequent generations of the parasitoids. Conclusion The results suggest that the CY diet could be considered as a standard diet for the multigenerational rearing of T. evanescens.