White-banded Ichneumon Wasp

With about 35mm this is a huge wasp. It is definitely a hunter, very busy. I photographed it in a mountainous region next to a creek. It was targeting a young Beech tree that was deeming with all sorts of life, molluscs, insects, spiders. There were a lot of flies and other ichneumonid wasps, also quite a few different beetles. I am confident this wasp belongs to the tribe Ichneumonini. It is extremely difficult to find picture representations of European Ichneumonids. The reason being that this taxonomic group is being commercialised. I found a 99% picture match. Unfortunately, it belonged to one of the less trustworthy biological control companies advertising for moth control with a picture of this large wasp. Of course, the picture has nothing to do with their product and there is no identification provided. The best match was Achaius oratorius. This is a wasp that figures on a Swiss census list, but doesn't seem to be very common. This wasp has a white patch on its shoulder. The first segment of its abdomen has two white bands, one towards the head the other one towards its tail. The white looks yellow through the smoky coloured wings. The abdomen is a bit longer than the wings. Its legs are long, spurred, black and white banded. Antennae show the typical white band as well.