About the Authors
Swiss Bee Research Centre, Agroscope Liebefeld-Posieux Research Station ALP, Bern, Switzerland
Bee Research Laboratory, United States Department of Agriculture-Agricultural Research Service, Beltsville, Maryland, United States of America
Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa
The authors have declared that no competing interests exist.
Conceived and designed the experiments: BD PN. Performed the experiments: BD. Analyzed the data: BD JDE YPC. Contributed reagents/materials/analysis tools: BD LG PN. Wrote the paper: BD JDE YPC LG PN.