After mentioning robber bees to a friend of mine in Canada she sent me a link to an interesting article.
It is unfortunate that my bees are really not having a good time of it and are still being robbed daily by hundreds of bees. One interesting point made by the author of this piece is the fact that the robbers acquire the hive smell by floating around the entrance in an attempt to disguise themselves and be accepted by the guard bees. This fits with the behaviour that I had seen when robber bees had more or less walked right past the guards with not so much as a momentary pause. A very worrying fact as I had restricted the entrances down to the width of two bees and put up the robber screen. I have also placed the bait hive nearby but they are not even remotely interested. As a result of the robbers the colony numbers have shrunk to a mere fraction of that which I had when they arrived as a nucleus hive so I envisage them ceasing to exist long before winter is over.
The dearth is still active around here hence the continued robbery.
On a lighter note another interesting article came my way from a friend in Washington State, USA. It relates to the provision of nectar bearing flowers in the late part of the year. The author is a scientist (Professor) involved with studying the behaviour of bee colonies.