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Sunday, December 27, 2015

GENETIC IMPROVEMENT by beekeeper Fred

Beekeepers frequently talk about improving the genetics of the bees in their apiaries.  The genetic traits most often considered are hygienic behavior to combat varroa, resistance to foulbrood, overwintering capability and honey output.   Improving the genetics is not as simple as a one time buy of a queen (as most beekeepers mistakenly think).  Difficulties arise due to the mating behavior of the queen honey bee. 

So you go purchase a queen with the genetic traits that you want.  Usually such queens are mated in somewhat controlled conditions.  The queen breeder controls mating conditions by flooding the mating area with drones of the same basic genetic makeup as the queen.  Conversely, in open mating areas (ie. Your apiary) drones are from the surrounding area with various uncontrolled genetics.  
So now you have your new queen.  So far, so good.  The first generation of workers raised from this new queen will have the desired genetics.  Also, the drones raised in this hive will also have the desired genetics.

Problems arise beginning with the second generation if the hive successfully re-queens itself.  The issue has to do with the mating behavior of honey bees.  The honey bee has evolved a mating system intended to prevent inbreeding.  This system prevents the mating of the virgin queen with drones from the same hive.  First, the queen leaves the hive about an hour later than the drones.  This prevents the drones from the same hive preferably mating with the virgin queen.  When the virgin queen arrives at the drone congregation area (DCA) she is met by thousands of drones from the surrounding area.  In the DCA only a small percentage will be from the queen’s hive.  Most of the drones in the DCA probably do not have the desired genetics you had purchased with your queen.  The virgin queen mates with an average of 17 drones.  In a few generations this behavior will dilute the genetics you paid for in your new queen.
   
The reality is that those desired genetics usually get passed on to a neighboring apiary, not yours.  Of course the next generation in your apiary may see return of those desired traits from your “now improved” neighbor’s bees.
 
So how can you improve your apiary’s genetics and have them sustained?
1)      Upgrade multiple hives with genetically optimal queens to increase the amount of drones with the desired genetics in the DCA.
2)      Understand apiary improvement is not a “one time” event.  You should plan on procuring new queens for several years in a row.
3)      If possible have a remote hive(s) with the desired traits at a separate site one to two miles away.
4)      Try to minimize the annual procurement of package bees and queens.   Remember the package bee suppliers have no financial incentive to provide you with better bees.  They are in the business of selling packages, which won’t happen if your bees survive!  This is exactly opposite of your goal.  The higher cost of better queens is another disincentive to the package bee suppliers.

Although it takes a little effort and perseverance, you should consider improving the genetics of your apiary.   Several approaches are available:
1)      Hygienic bees which remove varroa-infected larvae from the brood cells. These bees are usually labelled as VSH (Varroa Sensitive Hybrids).
2)      Primorsky Russian bees which have good wintering characteristics and mite resistance (both tracheal and varroa).
3)      Queens raised from survivor and northern stock

 Good books on this subject are:
- Mating Behavior of Honey Bees (Apis mellifera)

-Queen Rearing and Bee Breeding

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