It took me a while to find a name for this wasp, but according to my contacts at bugguide.net this creature belongs to the subfamily Eumeninae, in the family Vespidae. This group comprises the potter wasps and mason wasps—fitting appellations since this one built a nest right inside my mason bee condo.
At first I thought it was a parasitic wasp preparing to lay eggs inside a mason bee nest. But I watched carefully and noticed it was entering empty bamboo canes, not full ones. Then I saw it wall up the tubes with fresh mud. This particular wasp—or another dressed exactly the same—filled four tubes before she disappeared. So now I have bees and wasps all living under the same roof . . . equal opportunity housing.
Apparently, the members of this group are extremely difficult to identify down to genus. According to some sources, potter wasps are different from mason wasps, and I don’t know which one this is. With insect i.d., I’ve learned to be happy with anything I can get.
The potters and masons are solitary wasps that construct nests of mud or sometimes use the abandoned burrows of other wasps. Some species nest in cavities they find in wood. The female provisions her young with moth or beetle larvae, but the adult wasp feeds on nectar. The females can be seen foraging on flowers in summer and fall.