Hi Alison, good ID on the Melophorus, but it is the other common(ish) species, M. perthensis. Melophorus rufoniger tends to have a dull look about it, rather than the shiny look of M. perthensis. You can also see in your photos the shape of the propodeum (the saddle at the back part of the main body) which is relatively short and flat on the back, while for M. rufoniger it is longer and more rounded. Cheers, Jon