Thanks to bugguide.net, I learned that this visitor is Euodynerus crypticus, a mason wasp.
Nesting in small colonies, E. crypticus digs a vertical burrow in the ground, sometimes bringing water from elsewhere to soften up the soil. The eggs are laid in individual cells, sealed off with clay, and furnished with caterpillars, which provide a ready-made meal for the larvae when they hatch. This species specializes in the caterpillars of skipper butterflies....
Despite having started out life sipping caterpillar innards, this adult E. crypticus obviously likes the nectar which Bee Balm has to offer!
At that same time several individuals of a second species of mason wasp came to sample the libations at the bistro.
A braconid wasp also came for the bistro's food and drink. Maybe she is also looking for a caterpillar or beetle on which to lay eggs.
