Joergensenella, a new subgenus of Neotropical Megachile (Hymenoptera: Megachilidae), with a key to Argentinean Megachile with specialized facial pollen-harvesting hairs

A new subgenus of Megachile is described for the Neotropical Region. It is distributed in Argentina, southern Brazil, and Uruguay. The males of Joergensenella n. subg. run to Chrysosarus in available keys to subgenera of Megachile , and have been included as such in recent catalogs , while the females run in the keys, and have been included in catalogs, as Dasymegachile or Cressoniella . Association of sexes for all the species are presented for the first time. Besides the type species, M. joergenseni Friese, the following are included in the subgenus Joergensenella : M. bruneriella Cockerell, M. una Vachal, M. lujanense n. sp. (from Mendoza, Argentina), M. fidalgoi n. sp. (from Jujuy, Argentina), M. puntana , (from San Luis and Tucuman, Argentina), and M. yana n. sp. (from La Rioja, Argentina). Females of one of the species included, M. ( Joergensenella ) una , bear specialized hairs on the face for the collection of pollen from nototribic flowers. A key is presented to separate this species from other two Megachile in Argentina with a similar specialization: M. ( Dasymegachile ) schwimmeri Engel, and M. ( Cressoniella ) boliviensis Friese .