These are images of a Digger Bee or Centridine Bee, in the subgenus Paracentris, that I believe is most likely a female Pallid Bee, Centris pallida. (Former Subgenus = Xerocentris)
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ID Info:
Keying to Genera of Tribe Centridini: Snelling (1984)
Here is a link to the key, from the Natural History Museum website: Studies on the Taxonomy and Distribution of American Centridine Bees
1. - Marginal cell of forewing shorter than distance from its apex to tip of wing; occipital flagelliform setae usually absent, but if present, not reaching as far back as anterior margin of tegula = 2
2. - Occipital flagelliform setae absent; mesosternum of female without tubercles; hypoepimeron flat or slighly convex; pronotal lobe low and moderately convex; never conspicuously tuberculate = Genus Centris Fabricus
Keying to Subgenera of Genus Centris: Snelling (1974) (Keying on DiscoverLife.org gives similar results.)
Here is a link to the key, from the Natural History Museum website: Notes on the Distribution and Taxonomy of Some North American Centris (Hymenoptera: Anthophoridae)
1. - Maxillary palpus four or five segmented; hind leg of male usually not swollen, basitarsis without spine on posterior margin = 4
4. - Female gender ♀ (10 flagellomeres & basitibial plate on hind-legs) = 5
5. - Secondary basitibial plate without distinct overhanging margin = 9
9. - Scutellum not bilobed, without bare areas; smaller species = 10
10. - Mandible without tooth on under surface (Subgenera Paracentris + Xerocentris + Wagonknechtia) = 11
11. - Fore and mid basitarsi without setae which are differentiated from dense pubescence = Subgenus Xerocentris Snelling (1974)
Keying to North American Species of Subgenus Xerocentris: (now considered subsumed by Subgenus Paracentris)
Keying Females:
1. - Maxillary palpus four segmented; abdominal terga with dense, appressed, pale pubescence obscuring surface; thoracic pubescence pale, fulvous (brownish-yellow) tinged above; pygidium truncate, median ridge broad to apex = 2
2. - Mandible tridentate; abdominal sterna II-IV with pale, pubescent fasciae on margins; clypeus often maculate = Species Pallida Fox (1899)