Reassessment of Incasarus (Hymenoptera: Andrenidae: Protandrenini) with the description of two new species (Hymenoptera: Andrenidae)

A revised classification is presented for a group of Andean bees from Argentina, Bolivia, and Peru previously assigned to Liphanthus Reed (Andrenidae: Panurginae: Protandrenini) based on a phylogenetic analysis of 108 morphological characters. The results indicate that these species form a well-supported clade with the previously monotypic genus Incasarus Gonzalez, Rasmussen & Engel, rendering Liphanthus, as currently delimited, paraphyletic.

These species share several distinctive morphological characters, including dense to crowded punctation on the head and mesoscutum, strongly sculptured tegulae, and unique genitalic features not observed in Liphanthus. Accordingly, we transfer the following species to a redefined Incasarus: I. abotorabi (Mir Sharifi & Packer, 2019) comb. nov.; I. aeneiventris (Friese, 1908) comb. nov. treated here as the senior synonym of L. fritzi Mir Sharifi & Packer, 2019 syn. nov.; I. amblayensis (Mir Sharifi & Packer, 2019) comb. nov.; I. ancashensis (Mir Sharifi & Packer, 2019) comb. nov.; I. cochabambensis (Mir Sharifi & Packer, 2019) comb. nov.; and I. yrigoyeni (Packer, 2019) comb. nov.

Additionally, we describe two new species: I. arequipensis Romero & Packer, sp. nov. from Peru, and I. ivari Romero & Packer, sp. nov. from Bolivia, producing a generic richness of nine species. The phylogenetic analysis suggests three distinct lineages within Incasarus. This study enhances our understanding of the diversity of Protandrenini in the Andes and highlights the continued value of museum material and new field sampling for the discovery of diversity within poorly understood lineages.