2017/12/20 by Decourty, Axel, Vallon, Julien, Kretzschmar, André +7
#0 #Apiculture #Apis mellifera L #Epidemiology #Mortality #Mortalité #Observatoire #Observatory #Épidémiologie
paper · doi:10.15454/1.5137776881436677e12
During the last twenty years, the persistence of productive honey bee colonies became a major issue of beekeeping farms. The high rate of winter losses in colonies drags down the economical results of farms. The weakness of populations at the beginning of the wintering period has turned out to be a major explaining factor of these losses. We looked for early indicators of the risk of losing colonies throughout three winters (from 2012/2013 to 2014/2015) in order to better understand the factors impacting this risk. Towards this goal, a surveillance network based on 1318 colonies of professional transhumant has been created. The major biological threats associated to colony losses have been the varroa, the virus of deformed wings and the virus of the queen black cell. The size of the population (brood, adults) and the quantity of stored honey are also key factors. Although the importance of such or such factor is variable according to the geographic area, we have been able to define the ideal profile of the colony during the fall period that would maximize the chances of its survival during these three winters: 2 frameworks of brood, 5 frameworks of honey and less than one phoretic varroa for a hundred workers after treatment.