This subject is difficult to get a true answer about being weaker . I have watched many changes in the bees over the last 45 years.The problem I have is the fact that our environment has changed so much that it is hard to say , weak bees.
 I do see bees today that are slower in the spring than years ago. One note: 40+ years ago I had a call from the state bee inspector for the Olympic peninsula Wa. He was 80 YO and had bees for 40+ years. He told me  " Kid , that hive you have in Grape view is the meanest hive I have ever seen in my life. It was April on Apple blossoms and the hive was in 5 deeps. I split it 5 ways. I had to use the bee brush to swipe the bees off of the veil so I could see. We don't want bees like that at any time.
 Looking over my notes , I can see weather and location a big factor of hive performance . Every yard had variables . 
Over the last 6 years I have not moved any bees. I could see a difference in the queens . Genetic traits are not consistent with the queens workers.
 I have to go along with Randy's Bell curve   . That is what I see in my bees. I think multiple Drones is one factor. 
I do think that sex Alleles plays into the equation also. It is hard to get the numbers up without new stock.
Best Regards
Roy Nettlebeck  
              

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