By the way, thymol in sirup is not approved for the treatment of nosema. I don't care if you do it, but if you contaminate your honey you have only yourself to blame. Also, fumagillin is not approved in European Union countries; they don't allow any antibiotics in hives.> The relative weight of nosema disease in the mortality of overwintered colonies is a controversial matter. Higes et al. and Martin-Hernandez et al. attribute a major effect to Nosema infections in the mortality of colonies. However, there is no conclusive evidence to affirm that Nosema is an important factor in the recent honey bee die-offs worldwide.
> Certainly our results do not support the arguments of Higes et al. and Martin- Hernandez et al. It is possible however, that the same honey bee parasites may cause varying degrees of damage depending on their geographical locations. Nosema disease and tracheal mites did not show a significant effect on bee populations [in Ontario].
Ernesto Guzman-Novoa. 2010. Varroa destructor is the main culprit for the death and reduced populations of overwintered honey bee (Apis mellifera) colonies in Ontario, Canada