LLoyd, having followed Bee-L for a fair period of time now, your comment:

"Resistance is widespread in the US, and I know few beekeepers who still
treat."
relating to Acarine came as a surprise.
Reading bee mags., visiting various gov't. apicultural sites and the noting posted advice, plus the
many comments on this mailing list does not suggest to me that resistance is widespread - presuming
that you meant widely present in the bee gene pool and not just existing over an extensive area.
Am I totally blind (admitted, sight from this side of the Atlantic is difficult to ensure 10/10) in
thinking that major losses occur when preventative treatments are omitted?
What are the thoughts from Canadian side of the border?

Waiting to be told that I am blind!!

Regards
Peter
Parc Naturel de la Brenne
Centre West France