There is at least one trait/mechanism of resistance to varroa that is well identified, heritable, apparently present in most honey bee populations, and it produces declines in mite populations of colonies. When fixed to the right level colonies do not require treatment. It has been shown to work in a variety of settings and environments. It was first found over 25 years ago. It took a while to figure out the exact mechanism, but it is now clear that it comes from adult worker behavior.
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