Seven replacement names for bees in the genus Protandrena Cockerell, 1896 (Hymenoptera: Andrenidae: Panurginae)

The Protandrenini is a New World tribe of 436 species of andrenid bees (Ascher & Pickering 2022, Bossert et al. 2022). The North American protandrenines form a single clade (Bossert et al. 2022, Ramos et al 2022) of 186 species (Ascher & Pickering 2022). Over the past 170 years, the North American protandrenine bees have been placed in many different genera, including Panurginus Nylander, 1848 and Psaenythia Gerstäcker, 1868 (Michener 1944). More recently they have been considered to consist of between two (Ascher & Pickering 2022, Michener 1944, Michener, 1951, Mitchell 1960), three (Michener 2000, 2007), five (Ramos et al. 2022), six (Michener et al. 1994, Timberlake 1973), or seven (Hurd 1973) genera, sometimes including South American taxa (Michener 1944, 2000, 2007; Mitchell 1960). A recent molecular analysis (Bossert et al. 2022) has shown that none of these classifications adequately reflects the phylogeny of the group, all being paraphyletic. Pending further research, we believe the best solution for now is to recognize a single genus (Protandrena) with five subgenera: Anthemurgus Robertson, 1902, Heterosarus Robertson, 1918, Metapsaenythia Timberlake, 1969, Pseudopanurgus Cockerell, 1897, Pterosarus Timberlake, 1967 and Protandrena (s. str.). A possible taxonomic alternative would be to recognize Pseudopanurgus along with Anthemurgus and the currently recognized subgenera of Protandrena (sensu Michener 2007) as genera. Unfortunately, however, it is not at all obvious that either Heterosarus (see Ramos 2011) or Pterosarus (see Ramos 2011, Timberlake 1967) is monophyletic. Far more extensive sampling is necessary to resolve the relationships of the North American protandrenines. In the absence of such a study, the one genus solution is most adequate to retain genera that correspond to natural groups. This results in seven cases of secondary homonymy for which we provide replacement names below. Only one of these species is relatively common, the rest being known from only one sex, often just the holotype.