Colony performances observed in apiary large surveys

Between 2009 and 2016, 300 to 600 honeybee colonies in 24 professional apiaries were observed annually during the lavender honey flow in Provence, France. Colony weight gain (GP) was modeled as a function of resource availability, population structure, health status, and inherent variability. Analyses highlighted that the quantities of capped and open brood critically determine colony establishment on honeydew, while excessive adult bee numbers and large reserve stores negatively affect performance. Two colony strategies emerged—dynamic and conservative. Varroa mite infestation was identified as the primary health constraint with a defined critical threshold. Pesticide exposure was assessed through pollen analyses and transhumance trials, revealing complex impacts of pesticide cocktails on colony weight gain and larval development. Results are published online for beekeeper access.