Since we are now discussing how to develop mite-resistant queens,   I have a
proposal that any beekeeper with some extra equipment can try:
 
When you catch a feral swarm this year, do not requeen it, and do not treat
it for mites (beyond surveying to see if mites are present).   The theory I'm
trying to test is that if a feral colony is strong enough to swarm in this
day and age, it must have at least some resistance to mites.
 
Even though probably 9 out of 10 of these swarm colonies will end up dying
from mites within a year or two, I suspect we will find enough successful
colonies to make the effort worthwhile.   Moreover, this is something even
small-timers like myself can try.   And if the colony dies, you will still
end up with a bunch of drawn frames, so the effort will not be without some
benefit to you.
 
How to tell a feral swarm from one out of your neighbor's hives?   Knowing
the territory (where are your neighbor's hives) helps, and you can check the
swarm's queen to see if she's marked.
 
 
W. G. Miller
Gaithersburg, MD