Viability and infectivity of fresh and cryopreserved Nosema ceranae spores.

The microsporidium fungus Nosema ceranae is an intracellular parasite that infects the midgut of the honey bee, Apis mellifera. A major limitation of research on N. ceranae is that the fungus is non-culturable and thus studying it depends on the seasonal availability of Nosema spores.