Antipodes
Queen Bee
Here is a photo I took today. It seems it doesn't necessarily need to have the enlargement to be a tunnel. Also, the adult fly does not need to be "obviously" visible on the bees themselves for there to be braula. I can't see them on these bees for instance. Once the photo is clicked on and opened, double clicking on it will zoom it in.I think I see what you mean about the enlargement of the tunnels at the terminal ends. I zoomed in to my photo and there doesn't seem to be any enlargement to those terminal ends.
I'm sure some must have survived, I just haven't seen it for a very long time. I remember it when I first had bees, over 35 years ago - my mentor pointed it out after having persuaded me to enter a comb of honey in a show!