Here, we report on a unique parasitoid wasp species of Toryminae reared from oothecae of praying mantids in the Mediterranean region. Based on the first available large specimen series, we transfer the species to Microdontomerus iridis comb. n. (from Torymus), describe the so far unknown male, designate a neotype, expand the known geographical distribution by adding new records from Greece, Spain and Turkey, and provide the first images of live specimens of the species as well as information on its larval biology. We also transfer Microdontomerus carayoni comb. n. from Idiomacromerus.