As per life span of a bee, the best work on this was done in Germany some  
years ago.  Foragers were marked at feeders, variety of tests of distance,  etc.
 
I'd have to look it up, but the gist was that forager bees have a finite  
life that depends on how far they fly.  As they add up the  miles/kilometers, 
they slowly wear out.  The overall summary was that in  good weather with readily 
available food resources (bloom), forager bees that  flew EVERY day, only 
lasted about 10-12 days.
 
We used that bit of information in some bee population models and found  that 
it worked well - during periods when weather is inclement, bees log fewer  
flight hours, so live longer.
 
We then dug out lots of papers where the authors marked bees - most of  these 
authors DID not know about or at least did not reference the German  studies. 
 Surprisingly, that same 10-12 day life span popped out of the  papers, so 
its appears to be a reasonable estimate.
 
However, nothing was said about urban versus farm bees.  Urban bees  MIGHT 
live shorter lives because of factors such as air pollution (i.e., Atkins  smog 
studies) or a higher chance of becoming a smear on the windshield of a  
vehicle.
 
Jerry



**************Get trade secrets for amazing burgers. Watch "Cooking with 
Tyler Florence" on AOL Food.      
(http://food.aol.com/tyler-florence?video=4&?NCID=aolfod00030000000002)

****************************************************
* General Information About BEE-L is available at: *
* http://www.honeybeeworld.com/bee-l/default.htm   *
****************************************************