A survey on Nosema apis infection in apiaries of Urmia, North-West of Iran

The microsporidium nosema apis is a protozoan parasite specific for the epithelial cells ofthe ventricles of adult bees. nosemosis occurs throughout the world. between february andmay 2002-2003, samples were randomly collected twice from 20 apiaries in urmia regionnorth-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. inthird and forth stage of study (february and may 2003) the infection was seen in one and 4apiaries respectively. the results showed the low infection rate in the early months of the firstyear of study that it was increased in next year. the reason of high infection rate in the secondyear of the study can be the result of more rainy and cloudy days in this period comparing tothe first year. this has caused the hone bees to stay more often in the hives and increasespores excreted and subsequently spore intake were raised.