Sphecodes sp.
This is a sweat bee, probably in the genus Sphecodes. The bees in this genus are characterized by their bright red abdomens and are commonly known as "blood bees". Members of this genus are kleptoparasites of other bees, meaning they steal the food material prepared by other species. The adult feeds on nectar.
Order: Hymenoptera
Family: Halictidae
Genus: probably Sphecodes
Photograph: © 2015 RKD Peterson
Date of Photograph: 23 August 2015
Location: Montana, Gallatin Co. (45o43'41" N 111o08'11" W)