> >When varroa mite levels are continually low enough in the colonies one
> >can discontinue treatment (once mite populations remain below the
> >economic threshold ).
>
> The fastest way to select for these queens is to not treat...
>...you will likely acheive your goal that much faster.

Maybe, but not necessarily.

The problem I see with that approach is that, if one of the mechanisms
being sought is resistance to varroa developing in the brood, and it should
be, the colonies exhibiting that trait could easily be swamped by
incoming mites from colonies that did not exhibit the trait -- unless
mite reproduction in all colonies is restrained somehow and by more
or less the same amount in all colonies under test.  Moderate use
of a miticide can keep levels to the point where they won't kill the
hives or cause a collapse that would distribute mites to colonies
that would otherwise have low levels.

Dee has some interesting ideas on selecting the hives that are most
resistant.  She says that it is not necessarily the hives with the lowest
natural mite drops that are the most resistant and explains why.  This
has to do with the resistant hives doing housecleaning on the mites
every so often.  At those times, they will have higher drops, in spite of
actually having fewer mites.

allen
http://www.internode.net/honeybee/diary/