There were two of these beauties flying around Beebalm (Monarda sp.), with their proboscis out and their wings flapping, just like a hummingbird. They did not seem to take notice to me, but did not take any interest in stopping for a crisp photo. Nevertheless, it was an amazing experience.
Found commonly feeding on Butterfly Bush, Beebalm, of which seem to be its favorites. It also feeds on various other garden flowers.
I believe photo four is a separate individual. Photo five may also be the same separate individual. Tell me which is your favorite, and I will put it as the first photo.