>After varroa mites first arrived in the late 1980s in the Santa Barbara
>area, honey bee visitation to blossoms in urban gardens plummeted to a near
>absence, as it did in the back country.  However, feral honey bee colonies
>have rebounded in both areas these past few years, with documented survival
>of some colonies over several years and a large number of swarms reported
>by residents during the last two years.  A two story shingled-sided Boy
>Scout house in Manning Park, for example, currently has eight colonies in
>its walls.  Inspection of a few of the older surviving feral colonies has
>revealed a low incidence of varroa mite infestation, with most of the
>reproduction in drone cells and very little in worker cells.

I wonder if the practice of limiting drone production in hives has helped
select for Varroa that are more "willing" to use worker brood?