Low natural levels of Nosema ceranae in Apis mellifera queens

Queens are the primary female reproductive individuals in honey bee colonies and, while they are generally free from . Nosema ceranae infection, they are nevertheless susceptible. We sought to determine whether queens are naturally infected by . N. ceranae, as these infections could be a factor in the rapid spread of this parasite. Queens were analyzed using real-time PCR and included larval queens, newly emerged, and older mated queens. Overall, we found that all tissues we examined were infected with . N. ceranae at low levels but no samples were infected with . Nosema apis. The infection of the ovaries and spermatheca suggests the possibility of vertical transmission of . N. ceranae.