Alternative hosts may increase rearing and possibilities of using Trichospilus diatraeae (Cherian & Margabandhu) (Hymenoptera: Eulophidae) for biological control. The aim of this study was to evaluate T. diatraeae reproduction with the alternative host Tenebrio molitor L. (Coleoptera: Tenebrionidae) with life and fertility tables. Twenty-five 24-h-old T. diatraeae females were individualized per Te. molitor pupae of the same age, who were replaced daily until their death of this parasitoid. Survival of T. diatraeae immature in Te. molitor pupae was 92.65%. Longevity of female parasitoids was 8.28 d with an innate density increase of 0.15, net reproductive rate of 37.50, finite rate of increase of 1.16, mean generation time of 23.67, and population doubling time of 4.52 wk. Te. molitor pupae are suitable for development and rearing of T. diatraeae.