I'm glad Trevor stepped in to add some info about local conditions in Auz
re: canola.

FWIW, I thought his comments on queen introduction were very well written,
and right on the money for pretty well everywhere I've been, but there were
a few local effects discussed subsequently. This situation sounds similar.

> The other disadvantage working canola is that bees tend to swarm
> and for some reason often don't raise a queen to replace the one
> that swarms..

Last year was the first year for us pollinating hybrid canola, and we
noticed that there were some problems with queens and attrition in hive
numbers over the season.  In fact I was going to comment on this, but had
not gotten around to it.

Another Alberta beekeeper who has been on the pollination job for many years
now mentioned the  unusual queen loss associated with canola pollination to
me before we started, and it turns out we also experienced this effect. It
is interesting to know that it happens elsewhere, and to get some more
insight into it.

We had almost 15% dead-outs or shake-outs by the time we wrapped for winter
last year.  (We don't have time to try to salvage hives during our short
season; either they make it or they don't).  We normally have about 5%
shrinkage from the end of splitting to wrapping time.  Add to this our
normal winter loss of 15 to 25%, and the annual attrition rate is high:
roughly  1/3.  I had wondered why most canola pollinators were buying
package bees each year.

In considering the swarming factor, I don't think that every hive that
succumbed over the season swarmed.  We were aware where the swarm pockets
were, and I don't think that accounts for all the unusual queen loss.  The
failure of bees pollinating hybrid canola to replace queens when necessary
is most interesting.  I would assume that this failure to raise queens may
well apply to supercedure too, and supercedure is ongoing in any beeyard in
one hive or another pretty well all the time -- normally.

This failure of bees to requeen places a burden on the beekeeper to either
somehow detect and requeen deficient hives during the flow, or to be sure to
cull them before winter.  Or, I suppose we could stick a cell into each hive
mid-season to see if they go for it.

We have concluded that we must start with more colonies this year if we wish
to have sufficient hives going into winter to keep our numbers up.

Another factor, one that may not affect you in Australia, is that canola
honey tends to be very poor for wintering, due to its hardness in the comb.
Hives put into winter on strictly canola honey have a hard time of it.

> No walk away method of re-queening here.

<G> That's what I love about this list.  You must have been reading my mind,
Trevor.  One of the ways I was thinking of getting a few more hives for
winter was by splitting while on the canola.  So I thank you for this
warning.  If we try it, we're going to have to be sure to use cells.

Or do you think that the failure to requeen is not at the cell building
stage, but somewhere farther into the process?  How is caged queen aceptance
on the canola?

allen