Mike,
I said "that possible causes could include....." .  Interesting to see that you stayed away from the old age piece.  If there is no degeneration of genetic material that comes with age then how come genetic defects are more common in the babies of older mothers(humans) and tests are carried out to determine wether the foetus is ok or not? 
A lot of medicines carry warnings about not using when pregnant - presumably because they can cause defects.  Queens are pregnant all the time and are exposed to the chemicals that beekeepers use to control Varroa.  Dave Cushman mentioned queens that live up to 7 years!  Do you really think that 7 years of exposure to chemicals like coumaphos/fluvalinate/flumethrin etc. etc. are not going to have an effect?  The defects are not of course usually noticeable in any physical deformity, as in humans, but the suspicion exists that the cause for the daughters of "older" queens being inferior to daughters reared when the breeder was younger is from a cumulative effect of some of these chemicals.  Worker bees come and go - queens are exposed to many treatments during their life - powerful toxins that are insecticides - to me it is illogical to think that there isn't some effect.  Anyway, this is all a bit off the original thread which was to compare swarm queens with supercedure queens.  I wouldn't use either in my production hives if I could I'd change them for my own queens that have been bred for the characteristics that I need to make my beekeeping business profitable and not go bankrupt.  
 Keith Benson asked:  "specifically how would a supercedure queen differ genetically from a swarm queen?"  I must say I am surprised with the question - I would have thought that the answer was obvious - the supercedure queen doesn't carry the swarming gene.....................hahhahaha!

Roger White
Superbee Cyprus.

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