Within the genus Torymus (Chalcidoidea: Torymidae), very diverse parasitoid strategies and adaptations to its hosts have evolved. Its larvae are ectoparasitoids and attack mostly larvae of various gall wasps (Hymenoptera: Cynipidae) and gall midges (Cecidomyiidae). We study the coevolution of the genus Torymus and its hosts and target the question what kind of host shifts occurred during the evolution of the group. For this, we reconstruct the first phylogenomic tree for the the genus Torymus.