In the article below, referenced earlier by Glenn, the authors state that there's a correlation between colonies that can survive varroa infestation without treatment and, their elevated behavior of uncapping and recapping brood.  The theory being that mite reproduction is somehow suppressed by uncapping.  The act of recapping is hypothesized as being vital in ensuring the high survival of the previously uncapped brood. 

What's not discussed is the reason why uncapping infested brood cells suppresses varroa reproduction.  The uncapping referenced in the article may not be what you're thinking. If you look at the figures in the study, you'll notice that the recapped cells where hardly uncapped at all. Instead, they had a small piercing in the center that was, at some point, filled in with darker wax - that's what the researchers used to identify "recapping". We've included bald brood in this discussion which, is likely a related behavior but different.  

 >A. mellifera populations are known to survive infestations by means of natural selection, largely by supressing mite reproduction, but the underlying mechanisms of this are poorly understood. Here, we show that a cost-effective social immunity mechanism has evolved rapidly and independently in four naturally V. destructor-surviving A. mellifera populations. Worker bees of all four ‘surviving’ populations uncapped/recapped worker brood cells more frequently and targeted mite-infested cells more effectively than workers in local susceptible colonies. Direct experiments confirmed the ability of uncapping/recapping to reduce mite reproductive success without sacrificing nestmates. Our results provide striking evidence that honey bees can overcome exotic parasites with simple qualitative and quantitative adaptive shifts in behaviour. Due to rapid, parallel evolution in four host populations this appears to be a key mechanism explaining survival of mite infested colonies.<

>Rapid Parallel Evolution Overcomes Global Honey Bee Parasite
Melissa Oddie, Ralph Büchler, Bjørn Dahle, Marin Kovacic, Yves Le Conte, Barbara Locke, Joachim R. de Miranda, Fanny Mondet & Peter Neumann
www.nature.com/scientificreports/      May 16th 2018<

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