Effect of Nosema apis and N. ceranae on honey bee Apis mellifera queen development

Nosema apis and N. ceranae are agents causing the disease called nosemosis in honey bee workers and queens.Few is known about the impacts of it on honey bee development.The royal jelly in queen cells was infected with Nosema spores to see whether and how it affects the development of honey bee queens.Seven groups of grafted honey bee larvae were established, and treated as follows: high and low concentrations of N. ceranae and N. apis, mixes of both species in both concentrations, and untreated control.After allowing nurse bees to fill the queen cells with royal jelly, an injection of 50 000 spores or 10 000 spores was added into the royal jelly.We found that only N. apis decreased the hatching rate of honey bee queens both in single and mixed treatment at high dosages, but we did not detect any morphological deviations in unhatched pupae.