Systematics of the diolcogastroid complex (Microgastrinae: Braconidae: Hymenoptera) from the New World

The genus Diolcogaster Ashmead is one of the dominant genera of the subfamily Microgastrinae (Hymenoptera: Braconidae). However, the monophyly of this genus is doubted by many systematists, but to date it has hardly been investigated rigorously. In this study, I focused on improving the systematics of the Diolcogastroid complex, the genus Diolcogaster and its related groups from the New World.;I investigated the phylogenetic relationships among Diolcogaster species and related microgastrine genera using fifty adult morphological characters and molecular data including 16S rDNA, 28S rDNA and COI. The results demonstrated the polyphyly of the genus Diolcogaster. The results determined some well-supported Diolcogaster species groups (basimacula-group, lelaps-group, and scotica-group) and a monophyly of combined anomus - and xanthaspis-groups. The phylogenetic data also demonstrated the monophyly of some Diolcogaster species: D. brevicaudus, D. erro, D. ippis, D. lacertosus, D. lenocinii, and D. simplus. However, Diolcogaster was maintained in its current definition as a separate taxonomic entity because the phylogenetic results are not sufficient to produce a robust and complete phylogeny to provide a framework for the stable taxonomic treatment due to its short and weakly supported internal branches.;The genus Diolcogaster is revised from the New World. A key to species is provided, and species groups and host relationships are discussed. Thirty-six species are newly described, and three known species are synonymized. Therefore, forty-nine Diolcogaster species are recorded from the New World. Two new monophyletic genera, Cuneogaster and Pallenogaster are also proposed from the Neotropical region with C. inae n. sp. and P. fulgoris n. sp. the key to the new genera was provided, and the features and relationships of Cuneogaster, Pallenogaster and several somewhat similar microgastrine genera are discussed. A checklist of the genus Diolcogaster from the World is provided to reflect its diversity and world distribution.