Moussa Tavassoli - Department of Pathobiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
Seyfollah Eiganinejad - Department of Animal Science, College of Agriculture, Urmia University, Urmia, Iran.
Shahin Alizadeh- Asl - Private practitioner, Urmia, Iran.

The microsporidium Nosema apis is a protozoan parasite specific for the epithelial cells of the ventricles of adult bees. Nosemosis occurs throughout the world. Between February and May 2002-2003, samples were randomly collected twice from 20 apiaries in Urmia region North-West of Iran. During this survey total of 487 hives were examined for infection with N. apis. In the first stage of study (February 2002), no infection was seen in hives samples, but insecond stage of same year (May 2002) the infection was seen in one apiary with 131 hives. In third and forth stage of study (February and May 2003) the infection was seen in one and 4 apiaries respectively. The results showed the low infection rate in the early months of the first year of study that it was increased in next year. The reason of high infection rate in the second year of the study can be the result of more rainy and cloudy days in this period comparing to the first year. This has caused the hone bees to stay more often in the hives and increase spores excreted and subsequently spore intake were raised

Nosema apis, apiaries, Honeybees, Urmia, Iran