An illustrated key to European genera of Microgastrinae parasitoid wasps (Hymenoptera, Braconidae) with a recent historical and biological perspective and a guide to available species-level identification resources.

An illustrated key is provided for the identification of the 20 genera of Microgastrinae so far known to occur in Europe. A brief review of 20 century progress on the group is given. Morphological terms are explained and illustrated, with special reference to the different systems of wing venation employed by past workers on Microgastrinae in Europe, and recommendations are made for future work. For each genus, an outline of species richness, host usage, developmental biology, and particular morphological features is given, and some species that may be difficult to place are highlighted. Available keys for species identification within genera are referenced, with comments, and attention is drawn to species more recently recorded or described up to January 2024. The value of accurate rearing data for parasitoids is emphasised. The references discussed provide a comprehensive overview of the most useful literature for future morphological work on European Microgastrinae. (Tobias), is proposed.