1. Institute of Biology, Martin-Luther-Universität Halle-Wittenberg, Halle, Saale, Germany
2. Honey Bee Research Section, ARC Plant Protection Research Institute, Stellenbosch, South Africa
3. Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
4. Department of Sericulture and Apiculture, University of Agricultural Sciences and Veterinary Medicine, Cluj-Napoca, Romania