Not sure if they're strong enough yet to cope with a shook swarm, they're a week away from 5-6 frames of brood emerging based on the only inspection I've managed so far. I'm can't do anything before friday but I've plenty of spare kit ready and made up and there is also a chance that it might not be my hive that has the problem, either way we need to sort it out before it does become a wider problem. It'll be two weeks since the last inspection and there was no sign at all of any problem in the hive, they were building up nicely, had plenty of brood, a flow was just starting and they were the bright spot in a miserable day of beekeeping (it's the hive in the photos I posted the other week).
None of the hives I cleared away showed any signs of robbing though one of them was packed with (open) stores, though if other hives close by have had siimilar problems I guess it's possible they might have robbed a neighbouring hive and bought it in?