Can a Simple Selection Program Predict Winter Mortality? Preliminary Evaluation of the Flemish Honey Bee Breeding Program Steers towards Selection by Exclusion

Introduction Colony winter mortality has been monitored in Belgium according to the international guidelines developed by the COLOSS network from 2008 onwards (Nguyen et al., 2010; Van der Zee et al., 2013). At the time, the empirically considered reasonable winter mortality rate was 10% (Haubruge et al., 2006), which is much lower than the on average 20–30% winter mortality rates reported in Belgium between 2008 and 2010 (Ravoet et al., 2015). The high presence of clinical signs observed in the studied honey bee population clearly pointed towards the involvement of Varroa destructor mites and viruses infections (Nguyen et al., 2010). Both causes have repeatedly been identified as the main drivers behind winter mortality not only in Belgium but across the world (de Miranda & Genersch, 2010; Genersch, 2010; Johnson et al., 2009; Meixner et al., 2014; Nazzi et al., 2012; Rosenkranz et al., 2010).