Crested Golden-waisted Fly

This species has not been identified properly and the name is made up by myself for my own use. The fly was quite nervous but stationary. It took a lot to scare it with my camera flash. Its appearance reminds of a wasp with a slender waist. First, it almost looked as if there was a hole like a bite out of its thorax. The top view shows beautiful golden hair around its waist.