Following devastating losses suffered by U.S. commercial beekeeping operations in 2006-2007, we initiated a prospective study monitoring a typically managed, large-scale (.70,000 hives), migratory commercial beekeeping operation over 10-months. Honey bees from 20 colonies were consistently sampled beginning with the introduction of a new queen in April 2009 (Mississippi (MS), through transport to summer foraging grounds in South Dakota (SD), and transfer to California (CA) for almond pollination (Figure 1 ). During our study, these colonies were exposed to antimicrobial treatments, transportation stress, different pollen and nectar sources, and three distinct geographic locations: MS, SD, and CA, (U.S.A.).