Red-legged Longtail Wasp

Body size about 15mm, about 30mm including ovipostor. This Gasteruptiid wasp is large but considerably smaller than the giant one in about 12cm previously documented. This specimen was photographed around our house. Actually, it eluded me for weeks and today I managed to get a glimpse of what it looks like in detail. I believe it hunts for spiders. It was also very interested in a piece of wood, in particlar a nail hole. It landed near the hole and explored it with its antennae. That was the rare chance to get a photo of it. The animal has this particular style in flight, going back and forth along walls, often near spider webs or vegetation. On several occasions it almost landed on me. So, it is not exactly avoiding contact with humans or large moving objects, but when disturbed it tends to fly off and not be seen for a long time. It seems to be territorial since it hang around in the area for quite some time now. Its morphology is quite typical for this taxon, large, nicely shaped eyes, short antennae, extremely long ovipostor with a white mark near the tip. Its abdomen leaves the thorax midway, giving the animal the look of a ski jumper in flight. The abdomen is pustulose and shimmering green when close and with plenty of light. The hind legs are huge, bulbuous, dark coloured, also with a white marking near the end. The front legs are reddish, cream and white. The animal matches the holotype picture of Gasteruption longipleurale quite well. Of course, it is likely that this species level identification is wrong. I forgot to mention that about half an hour after photographing this specimen, a much smaller wasp most probably of the same species was encountered in the same spot. At the time I thought it to be a juvenile. Update 10/0/2017: We definitely got a resident wasp around our house. It is exploring the same area all the time. A half-sized specimen can also be observed on a regular basis, never far from the large one with respect to time and space. It is harder to catch with the camera and is often gone quickly.