>Rinkevich, F. D., Moreno‐Martí, S., Hernández‐Rodríguez, C. S., & González‐Cabrera, J. (2023). Confirmation of the Y215H mutation in the β2‐octopamine receptor in Varroa destructor is associated with contemporary cases of amitraz resistance in the US. Pest Management Science.

A few weeks ago, I saw Joel Gonzalez-Cabrera give a special talk hosted by the Alberta Tech Transfer team. His ongoing research has found two single nucleotide polymorphisms (SNPs) in the US are changing whether amitraz, or it's metabolite DPMF, can enter the mite's cells to kill it. Some mites tested in Alberta are showing one of the same SNPs as the US population. Resistance found in France is due to a slightly different set of mutations but with the same effect. 

So yes, resistance is widespread and now the genetic mechanism has been identified. During this talk, I also got the impression it has only recently been learned that DPMF accumulates in beeswax. I don't know the breakdown time but it does make me wonder if high concentrations of amitraz, or amitraz delivered in ways other than Veto-phama's plastic strips, results in larger residues of DPMF in beeswax. 

Within a population, not all mites are resistant but from the maps JG-C showed, resistant mites are widespread across the US and in a concerning number of apiaries in Alberta. As far as I'm aware, this is the only genetic testing on mites to date and it confirms the mechanism of resistance. Other studies have been observing resistance using the Pettis test and variations of the Pettis test.

It was the most sobering talk I've seen all year. Hopefully this is unrelated, but I was in some hives a few days ago that have had Apivar strips in for a month and the colonies have significant DWV. 

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