Towards a Stable Host-Parasite Relationship Between Honey Bees and Varroa Mites Through Innovative Beekeeping.

Varroa destructor is a major factor in declining honey bee health worldwide. Conventional beekeeping involves multiple Varroa treatments, limiting bees' ability to adapt to the mite. To foster a stable host-parasite relationship, we tested an "innovative" beekeeping method with fewer Varroa treatments, focusing on its impact on honey bee health. We compared Varroa mite fall, immune responses, and seasonal dynamics of Deformed Wing Virus-B (DWV-B) in colonies managed under conventional and innovative practices. Viral loads of newly emerged honey bees and foragers were quantified three times during the season. Varroa mite fall was monitored and immune responses were assessed. In spring, bees managed with the innovative method had significantly lower haemocyte counts 48 h after emergence. DWV-B loads did not differ between groups in spring but were higher in summer in bees managed with the innovative method. After summer treatment, DWV-B loads and Varroa mite fall were similar between groups. Despite higher numbers in Varroa mite fall and DWV-B loads in summer, the innovative method reduced both by fall, ensuring healthy winter bee production and colony survival. These findings suggest that reducing Varroa treatments can support a stable host-parasite relationship while minimising negative effects on honey bee health.