Re: "Darwinian black box selection for resistance to settled invasive Varroa..."
The number of colonies suggested as a starting population is way too small. It takes a minimum of 200 colonies in a starting population of honeybees to avoid genetic erosion.
They suggest positive selection for varroa resistance while avoiding the effect of susceptible colonies turning into mite bombs.
NW Alabama, 50 years, 20 colonies and growing, sideliner, treatment free since 2005, 14 frame square Dadant broodnest