>
>
> >My question is does anybody have information on how effective glacial
> acetic acid fumigation of equipment is in killing off any EFB contamination
> on those combs and on brood boxes?  Also, does anyone know how long the
> bacterium stays infective on combs if they are just left to sit without
> bees on them?
>

Those are both great questions Mark.

Bailey (1959) found that  EFB bacteria can remain infective in the combs
for some time (I'm hoping to soon get more details).
In our own apiaries, we don't notice reinfection--the disease seems to go
away either after treatment with oxytet, or in mild cases, by itself.
We don't notice a particular problem from recycling boxes of used comb, but
we haven't done a controlled trial.
A study in Switzerland indicated that it takes 50,000 bacteria per bee to
initiate clinical signs of disease ( DOI: 10.1051/apido:200819), so it
appears that there needs to be a high bacterial load in order to cause
noticeable disease--similar to AFB.

I've also pondered your question about fumigation with acid, and have often
wondered whether that is why we see such beautiful brood patterns after
treating with formic acid.  It would be wonderful if someone could test
formic fumigation, since it is so easy.

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

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