> What happens to the bees if a person uses confectioner's 
> sugar with corn starch in it rather than powdered sugar, 
> which is 100% sugar?

Nothing at all.  The corn starch is absolutely harmless,
even in the case of getting it in open brood.

There is more indgestible "ash" in many types of honey
than there is corn starch in powdered sugar.

If you search the archives:
http://listserv.albany.edu:8080/cgi-bin/wa?A0=bee-l&D=0&H=0&O=T&T=0

for both "powdered sugar" and "powered sugar", you will find
my old step-by-step instructions from circa 2000/2001, and you
will also find a long discussion on the corn starch.

Long story short, there was a time when beekeepers mixed 
antibiotics with powdered sugar, and sprinkled the mix on 
the top bars for the treatment of low-level AFB.
(We were young... inexperienced... scared... easily led.)
While this MIX would kill any open brood into which it fell,
and in some cases, caused a serious break in the brood cycle
with very high open brood mortality (like 85% and up), this
was the antibiotic doing the killing, not the corn starch.

Note that the reason that it is called powdered sugar DUSTING,
is that it works when one DUSTS the bees with a very fine
dusting of poofed sugar, as ephemeral as cigarette smoke.
The way it works is that particles in the 5 to 15 micron 
range clog the mite tarsal pads, and they can't keep their
grip on anything, and fall.


I know that several people have advocated an approach where
powdered sugar is dumped onto the top bars in large quantities
like a half a cup per hive or more, and then brushed down 
between the top bars.  This approach clearly will not create
the fine particles that work, and will clearly never reach
all the bees in the hive.  None of these approaches have been
tested in controlled studies, so the ONLY method that is sure
to work is the more labor-intensive approach of "poofing"
each side of each brood frame.

If someone wants to do a controlled study to prove the efficacy
of the "dump and brush" approach, that would be fine, but
this alternative methodology should not be assumed to have
any value at all in varroa control, as it may not dislodge
any more mites than opening the hive and saying "boo!" in
an attempt to scare the mites to death.  In my view, those
who promote these "easier approaches" are doing a great 
disservice by misrepresenting these methods as "proven"
in the absense of any hard data at all.

Remember Sucrocide, and heed the cautionary tale!

The proverb is so old, they teach it in Latin 1:
"Non omne dulce bonum." -  "Not everything sweet is good".


 

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