Comparison of the responses of two races of honeybees to infection with Nosema apis Zander

Responses of New Zealand bees from Italian (Apis mellifera ligustica) and dark (Apis mellifera mellifera) races to infection with Nosema apis were compared. Newly emerged adults from five colonies of Italian bees and three colonies of dark bees were tagged, dosed individually with N. apis spores and placed in cages with undosed companion bees from the same colony. Dosed individuals were removed and examined at different times to measure progress of infection. Ai the end of the experiment, companion bees were examined to determine the spread of infection from dosed to undosed bees. There were no significant differences between the two races in either of these measures of response to N. apis, Bees from the different colonies were pooled according to race, and their responses (percentage infection and longevity of infected bees) to a range of doses of N. apis spores determined. These data also showed no significant differences due to race. (C) Inra/DIB/AGIB/Elsevier, Paris.