Things seem to be going well in all my colonies. They're all busy at their entrances. There are wasps near the entrance to every hive but they don't appear to be getting in. The Varroa counts are very low and there's pollen on all the base boards.
There may be a problem in Colony 4. There is no pollen on the base board and there are Wasps which are not being challenged at the entrance. This suggests that supersedure or swarming may have left them without a Queen. There is evidence that mature brood is still hatching out.
The Wasps are becoming more persistent. I saw at least half a dozen around the hives at dawn. If they get access to the hives then they'll rob until there are no stores left.
I was away from Oxford for the last week of June. It seems that there was a swarm on the tree in front of my out apiary on 28th June. I suspect that this was from Colony 4.
I have no real evidence that this swarm was from any of my hives. There seems to be less going on in Colony 4 -- less pollen on the hive floor for example -- but I can't be sure.