This diggerwasp already flew a few days around a a sunny Ivy (Hedera helix). I suspected it to be a male as they often appear before the females and it frequently made short stops on specific leaves which it then swiped with it’s abdomen to place a scent flag. The leaves were always located on height of about 150cm or higher.
I’ve captured it for identification and it turns out to be a male Crossocerus barbipes ., a common species in the Netherlands. Unfortunately he escaped during the photo shoot and I could not find him afterwards. Nevertheless a nice new garden species!
References1 Nederlands Soortenregister