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