Interactions between mites and Nosema in Pacific Northwest honey bees

The Microsporidian Nosema ceranae has been recently implicated as a contributor to weakened and collapsing honey bee colonies in many parts of the world. This "new" Nosema species may be more virulent, and may be out-competing or displacing another Nosema, Nosema apis, across much of the world. Nosema spp. disease is typically associated with overwintering colonies in climates with few days warm enough to fly. The Pacific Northwest of the U.S. has just such a climate and Nosema ceranae has been identified throughout much of the region. In this study, Nosema ceranae is tracked in both time and space in the Pacific Northwest. Age trends of individual Nosema-infected bees are examined, and finally, interactions between Nosema ceranae and the parasitic mites, Varroa destructor and Acarapis woodi, are examined.