Honey bees are highly effective managed pollinators of great significance to crop production worldwide. Reports on increased honey bee mortality in recent years have thus triggered numerous national studies to understand more about what factors affect bee health. Yet despite all these studies, our collective understanding of honey bee health has been hampered by a lack of collaborative transnational efforts following common protocols. The pan-European epidemiological study is based on the results of the EPILOBEE Monitoring, conducted by the European Reference Laboratory of Bee Health, in 17 EU countries. The study, published in PLOS ONE in March 2017, shows the value of such studies, and, remarkably, reveals that a beekeeper’s professional background, experience and apicultural practices are critical to honey bee colony survival.
The aim of this study was, in the authors’ words, to “identify the key risk factors surrounding honey bee colony mortality through data from the first surveillance program based on randomly selected participants and deploying standardized methods to monitor honey bee colony health, pests, diseases and management practices across 17 European countries”. The geographical spread of the study is significant. Surveillance began in autumn 2012 and continued through to summer 2014. A representative set of honey bee colonies was gathered through random sampling of apiaries and bee colonies in each of the 17 countries. Colony mortality rates were calculated by taking the data from apiaries where three consecutive visits had taken place (before and after winter and during the beekeeping season). Annual colony mortality was calculated by pooling the winter mortality and seasonal mortality for 2,332 apiaries for the first year and 2,426 apiaries for the second year. During each visit, beekeeping practices and clinical signs of the main honey bee diseases were recorded using a standardized questionnaire. The results of this stringently conducted study are very revealing.
Hobby beekeepers with small apiaries and little beekeeping experience had twice the winter mortality rate of professional beekeepers. Moreover, honey bees kept by professional beekeepers didn’t display any signs of disease during the apiary inspections, whereas the colonies of hobby beekeepers frequently showed symptoms of severe Varroa infestation. In the group with the highest winter mortality rate, the beekeepers were over 65 years of age, had not attended any training courses in the previous three years, kept no beekeeping management records, and had no formal beekeeping qualification. In contrast, the beekeepers in the cluster with the lowest winter mortality were 30-45 years old, had attended training courses in the previous three years, were members of a beekeeping organization, and had more than five years of beekeeping experience. A similar pattern was evident in the seasonal mortality clusters.
The study revealed that among the main factors promoting healthy honey bee colonies are the beekeeper’s professional expertise, experience and apicultural practices. Consequently, the authors of the study recommend that more efforts be made to train beekeepers in good apicultural practices and early identification of diseases.