Lars Krogmann

The Hymenoptera (sawflies, wasps, bees and ants) are a megadiverse insect order comprising phytophagous, parasitoid and eusocial insects. The largest proportion of hymenopteran diversity is exhibited by parasitoid wasps, which originated from wood-boring sawflies in the early Jurassic. The parasitoid lifestyle combined with a novel morphological structure, the wasp-waist, gave rise to the explosive species radiation of the Apocrita, one of the largest arthropod groups. Apocritan wasps may comprise 1-2 million extant species, of which only 5-10 percent have been described so far. A morphology-based phylogenetic tree of the Hymenoptera based on a recently published dataset is presented and used to highlight the most important evolutionary transitions in Hymenoptera phylogeny. This dataset comprises 273 morphological characters and 89 taxa, representing all hymenopteran superfamilies. The systematics of jewel wasps (superfamily Chalcidoidea), a morphologically and biologically highly diverse group of parasitoids is presented and analyzed in more detail. Finally the global ecological and economic importance of parasitoid wasps is briefly discussed.