Tracys Landing, Anne Arundel County, Maryland, USA May 24, 2014
Late in the day, a small patch of the forest trail was in sunshine and lots of these were flying, landing on the sunlit leaves, preening and foraging on the ground.
Closest I can see in the guide is ruficornis species group, Typical Nomad Bees, luteola subgroup aka Heminomada, e.g., luteoloides & imbricata