Perdita celadona Griswold & Miller, 2010
Biology:
Specimens labeled as collected on Oenothera are actually on plants now assigned to Camissonia (F. D. Parker, personal communication).
Diagnostic description:
Perdita celadona differs from other Xerophasma by the darker body and truncate rather than rounded or angled apical margin of the labrum. The female pygidial plate is pointed, rather than rounded or truncate as in other Xerophasma, and the mandible has a preapical tooth whereas other species lack a preapical tooth.
Distribution:
Apparently endemic to the eastern Mojave Desert in Clark County, Nevada, where it was active at dusk. Known only from the Virgin River drainage ranging from Mesquite south to St. Thomas Gap.