Do varroa mites actually carry viruses on them ?
Is it true that they are a major source of certain viruses.?
Whilst it is widely held that varroa is a vector for viruses, I took this to mean that the weakening of the bees caused by varroa
left them susceptible to viruses.

It would strike me as odd, that a parasite (which varroa is in relation to
Apis Cerana), would damage its host in such a way.