Hi all,
I am from Denmark, and I have my bees in Copenhagen, where we are many hobby beekeepers treating against varroa mites at different times.
The photos are similar to my own hives and others where the colony died due to varroa and acute bee paralysis / deform wing virus... You can see the brood area where some of the new bees died meanwhile they were hatching. Four of my seven hives took part in a research project and the analysis showed high amount of acute bee paralysis and deform wing virus in one of the samples, and this hive died suddently around november/december looking exactly as the photos. I have had bees for 20 years and I am good at spotting bees with deformed wings but I have seen none in 2022. The researcher told me he had also seen none in 2022...
If the colony had died earlier, the dead bees on the floor would have been missing, and you would only see the dead brood and the few bees on the frames. I often spot the queen together with the bees on the frames but not always.
So you have treated your bees and after that they somehow got new mites. Perhaps they got the mites by stealing honey from other colonies breaking down due to varroa or some bees from the surrounding apiaries passed by or they met the mites in the flowers...
Next question is what to do about it next year...
In Copenhagen, we are going to try for the first time to announce a week to be our "treating varroa together week"...
I am learning a lot from your beekeeping forum, and I hope you don't mind that I give my opinion.
Good luck to you and your bees.
Best regards, Kristin