1. BeeSources, Beekeeping Consultancy , Bologna 40132, Italy
2. INRAE, UR 406 Abeilles et Environnement, Avignon, France
3. Institute of Bee Health, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 161, 3003 Bern, Switzerland
4. Bee Institute Kirchhain, Landesbetrieb Landwirtschaft Hessen, Erlenstraße 9, 35274 Kirchhain, Germany; Behavioral Physiology and Sociobiology, Biocenter, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
5. Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, 3003 Bern, Sweden
6. Biointeraction and Plant Health, Wageningen University and Research, Wageningen, The Netherlands