Red-legged Hunting Wasp

Size about 8mm. The wasp was found near its home which is a dead tree trunk that broke at about three metres above ground. It was standing in the sun, had a few tiny holes, and seemed quite unstable, probably not far to be breaking with the next wind storm. I observed the wasp crawl, move up to higher ground. To my absolute surprise it all of a sudden it seemed to be swallowed, instantly gone. I had not seen the hole it must have gone into beforehand. Also, checking the photos, there are definitely too many legs, and it is quite clear that it was carrying prey into its nest. The wasp is quite dark, but has shiny red extremities, legs, and antennae. Abdomen is tapering into a pointy end. Wings large, covering much of the body. Eyes quite normal, large lateral eyes, small occelli. Antennae are starting parallel, pointing forward but not outwards. Taxonomically, I am always short with small wood nesting wasps. They never seem to look the same, and there are hardly any reliable representations of any of them. I think they are extremely common and therefore assume that pictures are somewhere hidden away. May they be hidden forever, and feed the families of a new generation of junior synonym creator, one day. Or may they turn up, be as obvious as to embarrass me for not knowing and being able to share.