I had previously only seen these on E. rossii, and there were plenty on a nearby one, but this was the first time on a stringybark. There weren't very many. Another one was apparently being attacked by coconut ants on an E. polyanthemos (sighting 4190791).
Thanks Jon I wondered about this one, as this specimen has hairs on its bum, which I don't see in the other images but they may just be a trick of the camera.