A question of Identity

Another eucalyptus has burst into flower today and look what I found on it!  At first I thought it must be an Australian bee, but then realised it was too smooth of body and yellow of legs.  Is it a hover fly?  It has these unusual markings on its back, much like examples of hover fly I found on the web, but the body does not seem flat enough.  Perhaps Paladian can  help me here?!
My extra is the original Blip I intended to post until I saw my mysterious visitor. Same eucalyptus.