It s not just a mater of bees being able to survive with the mites. The area that you are keeping the bees in with the length and severity of the winter will have a huge effect on the relationship between mite loads and winter survivability. So bees that can survive treatment free in the south may not do as well in northern climates.
Well said.
I have "read" that humidity, heat, and cold all play an important role. If one or more of those things are different, the mites may be more capable of increasing more, or less rapidly.. Remember as well, that if your neighbors bees all die from mites, that hive you have that is MANAGING their mite load might be overwhelmed when the neighbors mite bomb hive decides to explode.
My four Waynes queens hives HAVE mites... Checking them tells me I need to treat them... However... checking them a month later tells me the mite load is staying about the same. and a month after that, the mite load seems to be... about the same...
I have come to LIKE these bees so much, that I am biting my nails here.. They grow quickly, gather lots of honey, and are in general easy to work. I dont WANT them to die this winter!!!!!!!