Jim suggested
>please at least read the abstract of the cited paper.

Jim, I have the greatest respect for your analyses and comments, and do not
want to distract you from your honeymoon, but I think that we could take
this suggestion even a step further, and actually read the entire paper
before leaping to opinions!

I do not have the English version, but I read the original Spanish version
before it was sent for publication.

> While the exclusion zone for the extract seems
to be non-zero, one is forced to wonder what
the exclusion zone for pure ethanol alone would be.

The authors did indeed test negative controls of ethanol alone in petri
dishes, and they found that ethanol alone did not display antibacterial
property.

> The paper addresses the use of a substance
called an "ethanol extract of propolis"
rather than propolis, so it should be clear
that there is quite a bit of ethanol in the
mix applied to the cultured AFB.

As far as the amount of ethanol applied to the colonies in the field tests,
they added 6% percent propolis extract (at 10% ethanol) to 1:1 sugar syrup.
By my calcs, that results in a final solution of about half a percent
alcohol--roughly equivalent to  the amount in "nonalcoholic" beer.

Since the alcohol would quickly evaporate when it was sprayed on a warm bee
cluster, I really doubt that it had much direct effect upon the AFB bacteria
in the colony.

Before you respond, it is clear that the researchers should have added that
half a percent of ethanol to the syrup of the controls, but they didn't.
However, research by Dr Mark Goodman has also confirmed that alcohol is not
effective for sterilization against AFB.

>and I'm not about to spray my combs with any amount of ethanol, thank you
very much

Well, luckily for you, the authors also fed the substance in syrup!  It was
also effective applied in that manner.  Funny that you would be concerned
about getting such a tiny amount of alcohol evaporating on your combs, since
I haven't heard you express concerns about the benzaldehyde and other
ingredients in a bee repellent sold in this country.

It appears that at least some extracts of propolis may very well have
activity against AFB.  This is not surprising, since the reason that plants
exude the types of resins that bees collect is as a means of defense against
bacteria and fungi that might attack plant wounds or new growth.

Research by Dr. Marla Spivak has also demonstrated that certain propolises
(propoli?) exhibit miticidal effect against varroa when ethanoloic extracts
are painted onto the insides of the hives, or onto the frames, and allowed
to evaporate before introducing bees and mites (she is currently having
several cooperating beekeepers collect propolis from additional locales for
testing).

It would not be surprising if propolis is a component of the bee immune
system at the colony level.  Of course, its efficacy would likely vary with
the plant species available.

Most respectfully,
Randy Oliver

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