We establish a new genus for an unusual species of Peruvian calliopsine bees (Panurginae: Calliopsini) that was initially reported in the literature as an undescribed species of Spinoliella Ashmead that purportedly expanded the range of the latter genus beyond Argentina and Chile. Although the new genus superficially resembles Spinoliella, it is easily distinguished by a unique combination of characters in both sexes but particularly in the male hidden metasomal sterna and genitalia. A cladistic analysis of 82 adult external morphological characters including all species of Spinoliella, as well as species of the remaining genera of Calliopsini, suggests that this group is sister to a clade consisting of Spinoliella and Callonychium Brèthes. We describe and illustrate Xeranthrena imponticula Gonzalez and Engel, new genus and species, from males and females collected in xeric areas along the Pacific slopes of the Peruvian Andes. In addition, the phylogenetic study suggests two well-defined clades within Spinoliella and corresponding to the previously recognized subgenera, although we do not advocate for their reinstatement. We briefly discuss new putative synapomorphies for Spinoliella and, building upon prior revisionary work, we describe and figure five new species: Spinoliella aidae Gonzalez, Smith-Pardo, and Engel, new species; S. confusa Gonzalez and Engel, new species; S. propinqua Gonzalez and Engel, new species; S. packeri Gonzalez and Engel, new species; and S. polita Gonzalez and Engel, new species. In addition, we synonymize S. karhadra Rodríguez, Toro, and Ruz under S. rufiventris Toro and Ruz (new synonymy). We provide new geographical and floral records, an identification keys to all 17 recognized species of Spinoliella, and updated key to the genera of Calliopsini.