Brown Mason Wasp

Size 10mm. This small wasp suddenly appeared when I tried to find insects on our lilly pilly bush. It actually started to open an unripe fruit, biting through the skin. Actually, I thought it was interested in the lilly pilly fruit. A little bit later, the wasp landed somewhere else. It had a small larvae in its mouth. Identifying wasps based on information on the web is almost impossible. Even records within ALA are clearly ambiguous or sometimes matches with type specimens that are rather far fetched. I found a pretty similar looking animal on http://www.brisbaneinsects.com/brisbane_vespoidwasps/BrownMasonWasp.htm. There is only one Australian species in this genus in ALA and - of course - without picture representation. [I assume this is not a lack of available photos but a lack of willingness to share. Keep preaching open data! It is so great when other people share, isn't it, harvesting and minding one's own business is all that is needed in academia.]. Physically, the wasp has a dark head and thorax. Actually, the front part looks golden which I assume is cause by the reflection of tiny hair. The skin is pustulose. Antennae long. There are yellow spots on each side on the front of thorax, followed by black and some more yellow lateral spots. It looks as if the wasp were wearing a black thorax armor, the seam of the shoulder patches yellow. The waist is black and thin, going into a red abdomen, followed by a yellow-white ring, some black, and another yellow ring. The eyes reach far up to the top of the head, seem rather rectangular than oval. They have an indent where the antennae are. Ocelli at the top are close to each other, very visible. Update 24/3/2017: Observed an individual today, repeating the behaviour described above. This wasp is a specialised hunter of caterpillars that reside within our Lilly Pilly fruit. It opens the small, unripe fruit, flies away, comes back, fishes out the caterpillar (this time about 6mm), holds it under its body, stings it holding it in its front with its jaws, flying on a nearby horizontal leaf, repeats. It has a yellow band around abdomen that is not readily visible in my photos. I would also revise its size upwards, to about 13mm. The wasp clearly holds or embraces its prey with its two front legs while chewing it into a mash. This process seems to take several minutes (allowing me to get my camera not expecting the wasp still to be there actually but the caterpillar still intact by the time I made it). Update 28/10/2017: Two individuals observed. They are building a nest in a stack of wood in our garden.