Revision of Xanthomicrogaster Cameron 1911 (Hymenoptera: Braconidae), a rare Neotropical genus

The genus Xanthomicrogaster Cameron 1911 currently holds only four species, three of which were described from only one sex. By pooling data from the Area Conservación de Guanacaste (ACG) project, as well as the Canadian National Collection (CNC), we were able to examine many specimens of Xanthomicrogaster, thus enabling us to greatly extend knowledge on this rare genus. Xanthomicrogaster is now known to occur from southern Mexico to Argentina, and the first host records, from Pyralidae, Elachistidae, and Geometridae, are presented. Putative descriptions for eight new species, based on morphological and molecular data, are included, with six of these occurring exclusively in Costa Rica. Sexual dimorphism occurs in the color patterns of Xanthomicrogaster, and thus males and females cannot be positively associated without molecular data. A phylogeny of the genus is also presented, based on three of the four described species and specimens from the newly described species.