Unfortunately I've lost the photo :(, but hopefully the description will be enough.
I've seen 4 or 5 of these animals flying in and out of a hole in the ground that rises vertically on the side of a trail path in Filicudi, Italy.
I would assume they were wasps, especially because of the slender body, as opposed to the chubby look of common bees, violet carpenter bees, and so on.
The body was black and dull red, but I don't remeber which of the two color was the main one. I'm pretty sure there was either one or two trasversal stripes across the abdomen, but I think I remember the head too was of this red color.
ChatGPT hasn't really been useful.