Potter Wasp, Ancistrocerus sp, female.

ID to genus level by BugGuide.org; ID to species level probably not possible -- there are 100+ Ancistrocerus species in North America.

Females search assiduously through the willows at this site looking for caterpillars or other prey for the larvae in their nests.

Adults feed on nectar. This shot shows a female nectaring on Baccharis salicifolia (Mule Fat); some species are also
known to obtain “honeydew” from aphids. Males cannot sting; the female’s sting is said to be relatively painless.