I agree, but I would have thought most strains should be able to produce honey when conditions allow.
S
That chart looks remarkably similar, if not exactly the same, as Brother Adams - which is about 100 years out of date. I would suggest it is a bit like an MOT on your car: reliable at the time of issue.
To be completely clear, the selective breeding work done is usually on carnica (see
Coloss/JAR52.1.07). IMHO, this is because it has the best overall profile
as a starting point. It may be that mellifera can be improved in the same way but this will take considerable effort. Buckfasts, by definition, are continuously engineered to be among the best performers but they are not a homogeneous population. They are a synthetic hybrid and each breeders Buckfasts may be considerably different. The Buckfast bee is more of an approach, or an idea, than a race of bee. Nevertheless, many beekeepers swear by it because it performs so well.
The OPs question focused on swarming in particular so discussion about other aspects of a colonies performance are off topic.
Carnica are generally held to be a swarmy race. I suspect that is because most people only ever encounter lower quality carnica from mass production multipliers. The carnica I work with are healthy, productive and reluctant to swarm (I have only ever had 1 of these swarm in all the years I have worked with them). So, the point should be that the carnica most people see is not a good representation of what a selected carnica can be. Of course, the same is true of mellifera and all the other races. They can be improved, but it takes work.
The real question is: are the people/groups we have in this country fit for purpose? Do they have the will/means to do the work necessary to improve mellifera in the same way carnica has been? Personally, I doubt it. All I see is a disorganised rabble more concerned with arguing than focusing on improvement. This is not the case in other countries though. There are mellifera groups all across Europe doing precisely the sort of selection work that I do with carnica. I am left with the conclusion that it is not so much the bee that needs improving, it's our attitude.