Malcolm
Good question. Queen balling is an interesting reflection of the social
behavior of bees.. a group decision, sort of "due process" rather than
"assassination". Perhaps that is its evolutionary advantage.
Jeff Pettis at Simon Fraser U. is doing some work on queen balling and
the pheromonal basis of its initiation.
Once I had an observation hive that went queenless. Rather than take it
apart and re-establish it, I tried simply letting a laying queen go into
the hive through a feeding hole on top. I watched as she walked a few
inches down over the comb, and as some workers congregated and started
to ball her (I don't remember any obvious agression). As I watched the
tight bundle of workers, I saw a queen walking away from the ball. At
first I thought there must have been a queen in the hive after all, but
I watched the ball for quite a while, it finally thinned out and there
was no queen inside. On the next day, the queen I had plopped in was
laying eggs. and they all lived happily ever after (sorry, I've been
reading to the kids).
I'm still interested in any chemical insights into the properties of
formic acid. We're now using a gel concentration close to the azeotropic
target (where water and acid evaporate at the same rate, so the output
(should be) more consistent over the 3 to 6 weeks of exposure. There are
a lot of variations possible.
Regarding the formic queen-loss observations, here's a possible red
herring, but I heard something similar from 2 beekeepers, so perhaps
it's something else to keep in mind.
On both these occasions, after formic treatment, "emergency" type queen
cells were observed, suggesting queen loss. Within a week, however, the
cells were destroyed and a queen (one beekeeper noticed slightly frayed
wings indicating an older queen) was observed laying eggs. Does this
suggest a masking or disruption of the queen "recognition" by formic
acid? There could be a link here with other formic -induced queen
losses. Another report indicated more loss of queens from a specific
source ( aw why not, they were Hawaian queens introduce a couple of
months earlier). A couple of beekeepers are convinced the queens that
were lost were old queens, others think they were mite infested..we
quickly get to speculation here. A clearer but uncontrolled observation:
formic application #1 was put on a set of hives, all OK. The beekeeper
then received an order of queens (10 ish), split the colonies..and time
came for application # 2. What to do? (What not to do: he treated both
the parent hives and the splits, with the queens within a couple of days
of introduction.. and half were queenless a week later). What I would
have suggested: Put lots of capped brood with the queen being
introduced. Move the "splits" to the other end of the yard for a couple
of hours to days, allowing the field bees (with mites ready to migrate)
to drift back to the parent hives. Continue treating the parent hives,
but not the splits (this manipulation is as effective as chemical
treatment).
Back to the formic-queen observations. There's probably some elegant
chemical explanation buried in there. In practice, when 30 - 45 ml of 65
% concentration acid has been applied to 2-std- box hives when the
temperature has been below 30 deg C, the loss has usually been
unnoticeable, but occasionally suspicions of losses up to 20 % occur.
With 85 % formic, or at temperatures above 30 C or 90 F, and/or where 65
% acid has dribbled down into the cluster, queen losses of 50 % to 10
out of 10 have been reported.
I'll continue to be interested to hear any other reports.
Kerry Clark, Apiculture Specialist
B.C. Ministry of Agriculture
1201 103 Ave
Dawson Creek B.C.
V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299
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