The full name of this pollinator is the Gold-marked Thread-waisted Wasp (Eremnophila aureonotata). Apparently it needed a name as long as its thread waist.
It was a frequent visitor to the Mountain Mint (Pycnanthemum muticum) I planted in my Dad's yard. This Mountain Mint is also known as Short-toothed Mountain Mint or Blunt Mountain Mint.
The first year I planted the mint it attracted a large number of pollinators, especially small solitary bees. The small blossoms open over time, starting at the center of the inflorescence and working to the outer edges.
Location: Suburban Backyard, Mt. Vernon, VA