Deknow, I'm familiar with the hair pulling. These bees are far too numerous to be veteran robbers. They all have the same pattern, and I didn't see them from a distance, as I was saying I would sit next to the entrance and watch the bees for hours. They are black tipped, about 1/3 the length of the abdomen, with the second third having a thin band of yellow, a thicker band, and the thickest with a hair thin line of black in the last third.
I would say about 2 mm shorter than the regular Italians and thinner bodies. I thought they might be robbers as well, and there were plenty of fights, but there were so many of them I figured they were different genetics coming out. The trees around here have plenty of rotten branches and trunks, so I can only suppose they came from there or the neighbor's hives across the road.