Submitted to: Zootaxa
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2007
Publication Date: 6/24/2010
Citation: Griswold, T.L., Miller, W. 2010. A revision of Perdita (Xerophasma) Timberlake (Hymenoptera: Andrenidae). Zootaxa. 2517:1-14. Interpretive Summary: Bees of Perdita subgenus Xerophasma are poorly known and rarely collected in part because of the flight activity only at dusk and perhaps at night. Their flight time is presumably related to flowering in evening primroses (Camissonia, Oenothera), the only plants they visit for pollen. We describe three new species of this rare group, all from the eastern Mojave Desert, and present a key to distinguish the species. We also discuss the increased body size, and enlarged simple eyes that appear to be the result of evolution in the group.
Technical Abstract: Three new species of Perdita (Xerophasma) endemic to the Mojave Desert are described: P. celadona Griswold and Miller and P. vespertina Griswold and Miller from Clark county, Nevada, and P. rhondae Griswold from Death Valley, California. The subgeneric description is redefined to accommodate these new species. New distributional records for P. bequaertiana and P. pallida and a key to the species of the subgenus are provided. A well supported phylogeny suggests evolution toward nocturnal foraging expressed in increasing ocellar size and a trend toward totally pale integument. The apparent origin and center of diversity is the eastern Mojave Desert.