Tachinid Fly

At first I thought I had captured a bee when I returned to the Myoporum (my FF Blip) today.  However, I soon realised it was neither a bee nor a wasp so I started researching on the net.  All I can come up with is that it is probably a Tachinid fly - Family Tachninidae. Apparently they are very diverse in appearance, sometimes wasp-mimicking. They are parasitoid in habit.  I can't bear to go any further in defining this. It involves hosts and larvae and...... No, can't do it!
I really have no idea what I am offering as my Blip today. I was OK until I came across the word "fly".  That was enough. After all, I am an Ozzie! Can anybody tell me this is a good insect to have in our garden?