White-bellied Rutilia Fly

Size about 23mm. This is the biggest normal shaped fly I have ever seen. It was at about 2 metres on a gum tree with very groovy bark. I could clearly see the abdominal hair bushes, a tail that looked like it was split in two, and the white pattern on its belly. Unfortunately, this fly is not only huge, but also very fast - faster than my camera shutter and flash can catch the photo. The animal was showing remarkable rapid response reflex, came back the first time, but vanished after the second photo. This species is said to feed on beetle larvae, which must be plenty where it was found. There is quite a bit of dead wood nearby where lots of insects are feasting.