Randy,

Thanks, Waldemar


>>>>>>I've read in some places that, when the bees ingest OA/sugar syrup, 
it changes their blood pH.  As mites suck the blood or perhaps lose 
the taste for the altered blood, it causes them to die.>

This was an early hypothesis that I think Nick Aliano's work put to rest.
The best current hypothesis is that the spiky crystals of OA puncture the
mites--causing dessication or poisoning, but this could be wrong.
If you evaporate an OA solu in water, you get tiny spikelike crystals.  But
if you evaporate it in syrup, you just get a clear "gel" in which I don't
see crystals.  So I have more questions than answers.


>>>>Syrup that lands on the frame tops does not count--the bees don't touch it!
I was oversimplifying--I will revise.

>>>>>>Perhaps not initially but eventually they clean it up.  I think it 
must, at least temporarily, end up in their stomachs.  When I checked 
a hive once after a treatment, I saw freshly deposited OA syrup in 
cells.  There had been no flying weather since the treatment.

How did you know it was OA syrup?

I tried this spring dribbling OA on nucs 5 days after queen cell emergence.
 The queens mated out normally.  OA in nucs is a great way to start
relatively mite free colonies.

In another experiment, we just finished spraying 15 colonies 3x at 5 day
intervals to really give them an OA hit.  There was no nectar flow on (this
is a huge question to me:  does a nectar flow make a difference?)  We didn't
set up the experiment well to look for young brood loss.  The colonies, 5
days after last treatment, have little young brood, but we don't know if OA
had anything to do with it.  We began stimulative feeding yesterday to see
how well the brood recovers.

If we can find more infested colonies, we'll try a controlled experiment,
marking brood, with a control group, and dribble with and without
supplemental syrup to simulate a nectar flow.

One problem for us Californians is that with bees going in the $150 range
into almonds in February, experimenting with colonies can mean a lot of lost
income!

Randy Oliver

-- Visit www.honeybeeworld.com/bee-l for rules, FAQ and  other info ---