Impacts of indoor mass storage of two densities of honey bee queens (Apis mellifera) during winter on queen survival, reproductive quality and colony performance

Spring imports of queen honey bees (Apis mellifera L.) are essential to replace winter colony losses in Canada, but contribute to the spread of treatment-resistant strains of pathogens and undesirable genetic traits. A possible alternative to these imports is the mass storage of queens during winter. By overwintering a strong colony (queen bank) containing large numbers of mated queens isolated in cages, beekeepers could acquire local queens early in the spring. In this study, we tested the efficacy of overwintering queen banks at two different queen densities (40 and 80). In the 40-queen banks (40 QB), 74.2% of queens survived the 6-month overwintering period, while 42.1% of queens survived in the 80-queen banks (80 QB). When compared to queens overwintered free in their colony, queens from bank colonies were smaller and lighter in early spring but had similar sperm viability and sperm count. Overwintering queens in banks did not have an impact on their acceptance in a nucleus colony but reduced their oviposition in the initial weeks following their introduction. After several days in nucleus colonies, queens from banks had regained a size and weight similar to that of queens overwintered normally, suggesting that they could perform well over a complete beekeeping season. This study achieved promising results and highlights the potential of this technique for the beekeeping industry in Canada and worldwide.