Thank you for your reply and awesome picture of the lavender field. I am an advocate of no treatment in America. So I have been collecting and selecting wild feral bees and have not treated my colonies for the past 20 years. My problem here in America is not V. Mites but Small Hive Beetles (SHB). I cannot make summer splits any more because SHB will devastate. As the split grows, they cannot patrol new areas where they filled up with honey and pollen because their numbers are still too small, or sometimes a strong colony can be wiped out in three days by SHB's. They came to America in 1991. It takes about a decade for a pathogen and a host to reach an armistice (South African and Swedish Studies). So all the feral bees live with SHB. All my bees jump at the sight of a beetle, showing they have learned to defend. So I gave up making nucs in the fall and try to make splits in the spring, starting this year. It sounds like you do not have SHB issues in France, which is good.
View attachment 308