At 05:29 PM 11/19/1998 -0700, you wrote:
>Garth wrote:
>
>> Hi All/John
>>
>> John, ... Bees in africa don't have a seasonal swarming urge, as much as
a seasonal swarming result. The queen burns out and they swarm.
 
> John wrote with all our history
>with "Holstein" queens, I've not thought of swarming as a response to
>queen "burn-out". ... don't believe all those big swarms are
>absconding, as we used to see. ....I'm confused..
 
 
Garth and John:  I have been measuring brood patches and assessing queen
performance in hives in Montana, Idaho, Washington for over 25 yrs and now
have done the same in Maryland for 3 years.
 
Those "Holstein" queens may be doing the same thing as Garth's African
Queens.  I do not pretend to understand exactly what is going on, but the
following is very clear:
 
1)  The rate of supercedure in both commercial and hobbiest hives is far
greater than commonly reported.
 
2)  It is not uncommon to find 20-30% of the colonies requeening right
after: a) the beekeeper stacks on a lot of equipment to catch a major
summer nectar flow, b) slaps down queen excluders, or c) uses a heavy hand
using chemicals to drive bees out of the honey supers.
 
3)  Queens can and do burn out in the sense that they run out of sperm and
become mainly drone layers - and under conditions of high stress this can
happen during the first summer of her residency.
 
4)  Late summer and fall supercedures, which may or may not be accompanied
by swarming, often occur in a colony that still has a queen that looks good
(swollen with eggs, bees in attendance) but the colony overall has not done
well (small population size, never grew very fast, etc.) through the season.
 
 
Years ago we conducted a very detailed study in which exposure to toxic
chemicals from an industrial facility caused heavy brood mortality in
colonies in commercial apiaries sitting downwind from the smokestacks of a
chemical, acid, and lead smelting complex.  Colony population sizes
remained good as did productivity, despite brood losses of as high as 80%
of the eggs and larvae.  The brood patches looked better than one might
imagine.  Apparently, the chemicals caused a large percentage of the eggs
and early larvae to die.  The bees would clean out the dead brood, and the
queen would re-lay.  Given the age distributions of the brood patches, this
happened 2-3 times.  Eventually, the queen and bees would manage to get
living larvae and pupae in most of the cells.  (So, the queen made up for
the initial losses by relaying over and over again).  The price that she
paid was that by mid- to late- summer, these queens became drone layers.
 
Now, we tried to publish that study, and the reviewers argued that we were
simply looking at poor queens (they reasoned that no properly mated queen
could run out of sperm in one season).
 
Some years later, we developed a computer model that included the ability
to calculate how much sperm a queen would use at different rates of
egg-laying.  Guess what, assuming even a modest rate of laying she was good
for 2-3 years or more (had sufficient sperm - even at rates of use of 10
sperm per egg or more).  But, if she started replacing and relaying at the
rates that we documented, the model always ran her out of sperm before the
end of the first season.  So - this result is theoretically possible.
 
Jerry
Jerry J. Bromenshenk
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http://www.umt.edu/biology/bees