>
> >I have seen the footpad comments but not the carapace. Was the OA
> anhydrous
> or the hydrated version?


It was the condensed crystals on the glass surface of a petri dish from
vaporization.


> My understanding is the hydrated OA (the form of
> OA that most use) first boils off its water then sublimates into anhydrous
> OA which condenses throughout the hive.


I haven't heard of any analyses of the condensed crystals as to whether
they were anhydrous or hydrated.  I would suspect that in a hive
environment following vaporization, that they'd by hydrated.  I'd be
careful about assuming that the crystals were anhydrous.


> Does the anhydrous OA have an effect when in contact with the mite's body?
>

I would assume that it would it it touched the empodium, since it would
immediately hydrate from contact with the moist fluid.

>
> From that, it is apparent to me that some clarity is needed when addressing
> the mechanism for mite kills since there seems to be a very definite
> difference in effectiveness between anhydrous and hydrated Oxalic Acid.


Only if one assumes that the condensed crystals are anhydrous.

Charlie's experimentation, as well as that of Nanetti and others, suggests
that adding a humectant (sugar, glycerin) to the dihydrate allows it to
much better absorb through the mite's exoskeleton.


> Both deposit OA crystals in the hive but the OA is not the same.
>

I would hesitate to make the above assumption.



-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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