The microsporidian Nosema ceranae, the antibiotic Fumagilin-B®, and western honey bee (Apis mellifera) colony strength

International audienceWestern honey bees (Apis mellifera) are under threat from a number of emerging pathogens, including the microsporidian Nosema ceranae historically of Asian honey bees (Apis cerana). Because of its recent detection, very little is known about the biology, pathology, and control of N. ceranae in western honey bees. Here we investigated effects of the antibiotic Fumagilin-B®, which is commonly used to control the historical Nosema parasite of western honey bees Nosema apis, on N. ceranae and effects of N. ceranae on colony strength (i.e., number of bees and amount of capped and uncapped brood, honey, and pollen) and colony mortality. Similar to our previous study, fall Fumagilin-B® treatment lowered, albeit weakly, N. ceranae intensity the following spring. However, N. ceranae was not associated with variation in colony strength measures or with higher colony winter mortality