Distinguishing Bees V Flies V Wasps

For a while yesterday morning we were watching honey bees foraging in one of the flowering Kurrajong trees near the sheep yards. The tree has a very heavy load of flowers and in this photograph is a single honey bee accessing pollen and nectar:

We noticed another species of insect being quite aggressive to the honey bees, and managed to capture the image of one of them ... below:

To appease our curiosity in determining the species of the aggressor we sent an email to members of the team room set up post attendance of the natural beekeeping course in Sydney earlier in the year. We asked whether any of the members knew what it was and attached the above photo. Within a couple of hours Louise Y responded saying that it was some type of hover fly and shared a hyperlink to the Queensland Government Department of Primary Industries and Fisheries publication titled "The Asian Honey Bee - A Guide to identification" located on the Animal Health Australia website. The document in fact is an excellent summary of the main things to look for in distinguishing bees from flies and wasps. Some information about Rainbow Bee-eaters is also contained in the publication, including the fact that they have communal roosts in the same location each night.