A small Castiarina I didn't think I had seen before.
About 10mm long; all metallic green and yellow.
Sexual dimorphism? Some C.flavopicta are 40% larger. Some are orange and blue. Patterns are larger and smaller than this diminishing completely in places. Many different coloured pronotum and head. etc.
Male fly called "March Fly" or "Lovebug" in the USA. (Both unsuitable names here). Previously classified in the family Bibionidae but now segregated into the family Pleciidae. Probably Plecia dimidiata as this is the only one on the ALA in Victoria. Males have large heads and eyes.