> it's the parasite/nutrition/lack of recruitment that takes the colony down.  The mite acts  a vector of viruses, and general stressor.

If it were only that simple! 

Dennis, et al, seem to be saying that there is not a direct correlation between mites and mortality, but rather mites and the melted brood disorder are in the same hive. They may be a vector also, but the brood disorder, whatever it is, kills the hive quicker than anything else.

They write

Our findings, as they relate to the symptoms
in brood (called here IBDS), do not support an association
with Varroa mites, as evidenced by a non-significant odds
ratio for the two factors. Indeed, even the reports that initially
described PMS suggested that the role of mites in the
symptoms in brood was likely secondary to the symptoms
described (Shimanuki et al., 1994; Hung et al., 1996). 

However, mites may play a role in creating IBDS by acting as a
vector for a causative agent or because mite feeding somehow
activates asymptomatic infections (Hung et al., 1996).

If IBDS is indeed a symptom of viral infection,
its persistence in infected colonies with low Varroa mite
pressure is not surprising considering that viruses are able
to persist in colonies even when mite levels remain low or
after they have been controlled with chemical treatments

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