> Might there be a genetic influence

No reason to suppose the two are not related, but then -- we don't really know why queens are superseded. Some queens are not superseded long after they no longer lay properly, and some are superseded in the first season though they appear fine to us. Similarly, some colony sail through the winter and some fail in December or January. 

To confound matters, however, there's the role of varroa mites and possibly nosema. Both of these can shorten the lifespan. So can certain types of honey. It's a major problem studying lifespan of colonies the health of which is already somewhat compromised. To me, all the more reason to try to keep varroa levels as low a possible.

PLB

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html