'Instead, the infection has been found only inside 
> the gut of the varroa, suggesting that the mite 
> has merely eaten it from the bodies of bees already 
> infected'.

I understand that the research found virus particles were concentrated in
the gut of the mite, and could not be passed back to the mouthparts because
of a membrane in the throat. That suggests the virus comes out of the mite
the other way - in the feces. I understand mites submerge themselves in the
residual brood food when entering a cell about to be sealed. Might the mites
then defecate into the brood food, so that the larvae eats virus and becomes
infected?   The daughter mites that are born in the sealed cell would then
become infected by feeding on the larvae.  And so the infection goes on and
on.  Perhaps that transmission mechanism explains why bees emerging from
cells entered by more than one varroa show shriveled wings - their food was
doubly contaminated.  
But as Jim says, does clarification of the transmission mechanism help at
all in the task of finding ways to break the natural cycle of infection?  Is
it likely we can protect the residual brood food from contamination?  Seems
a hard one. 

Robin Dartington  

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