What works in Texas might not be the same as what happens in New
England but what I have noticed is that the mites run in cycles where
one year they are very bad and as a result die with most of their host
colonies and the following 2 years they are relatively mild and the
cycle repeats. Like ticks it's not so much the bite as the additional
pathogens the mites pass around. Now that Apistan is no longer
controlling the mites I have halved the number of colonies I keep
because it just goes against my way of doing things to use the
Checkmite organophosphate acaricide.
I see no evidence of the bees developing a tolerance to the mites on
their own here.