#133 - Split-horn Sawfly
This one, when I saw it perched on a fig leaf, had me utterly baffled, because its antennae were forked.
I couldn't think of a single wasp or fly that had such a feature. Indeed, as you can see from this post at What's That Bug? a similar insect had an entomology professor baffled. Happily, Google came to my rescue and pointed me towards the Argid Sawflies. The males in some genera have bifid antennae. Indeed, in the genus Schizocera/Schizoceralla, the split horns are what it's named after. I can't say for certain that this is Schizocerella pilicornis, the Purslane Sawfly (it's a small wasp and the pictures aren't the best), but the Argids are very poorly represented in Australia otherwise, and S. pilicornis was deliberately introduced to try and control Portulaca. Its larvae feed on the inside of the leaves. The almost identical Schizocerella lineatus feeds on the outside.