About 8mm long, feeding on dill flowers. Males have a lot more yellow on their faces, rather similar to Hylaeus.

Comment from Matthias Buck on BugGuide:

'C. dentifrons is inseparable unless a specimen is available but C. arelate is much more common. Note yellow bands of equal width on segments 2-6.'
https://bugguide.net/node/view/129450/bgimage