1. Center for Infection and Immunity, Mailman School of Public Health, Columbia University, New York, New York
2. Department of Entomology, Pennsylvania State University, University Park, Pennsylvania
3. Bee Research Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, Maryland
4. Bureau of Plant Industry-Apiculture, Pennsylvania Department of Agriculture, Harrisburg, Pennsylvania
5. Department of Entomology, Hebrew University of Jerusalem, Rehovot, Israel
6. Center for Infectious Disease Dynamics, Department of Biology, Pennsylvania State University, University Park, Pennsylvania