I moved Colony 11 to another site in the hope that it would recover. I put honey in a feeder to bolster it. It didn't stop the robbing, although it did significantly reduce it.
Yesterday I plucked up courage and actually examined the comb in the brood area. There were no brood and I couldn't find a Queen. I decided that there was no point feeding wasps or other bees. It was time to combine Hive B (Colony 11) with Hive A (Colony 1).
Last night I shut the hive. At 7pm there was a great deal of activity at the hive entrance which suggested robbing by bees. I came back after 9pm and all was quiet. This morning at 5am I moved the hive back to my home apiary.
I used the newspaper combining method. Take the top off the destination hive. Place a sheet of newspaper over the top of the hive. Remove the floor of the source hive. Place on top of the destination hive so that both hives are separated by the newspaper. The smell of the two hives should mingle so that there won't be fighting once the newspaper is punctured.
I opened Hive A but left the crown board on top. I placed a thin stick on the crown board and laid the newspaper over it. I then cracked Hive B off its floor and placed it on top. The smell of banana wafted up from Hive A as its bees signaled alarm but only for a moment. The two hives were joined in under 5 minutes. The only near upset was when the newspaper blew off. Once Hive B was on top I made a tiny adjustment to its position and then regretted doing so. Newspaper is very easily torn so it would have been better to place it badly and leave it than to rip the paper. I think that I got away with it.
The bees from Hive A were flying strongly at 6:30am. I didn't see any evidence of fighting. I'll look again later in the day.