The first report of the prevalence of in Bulgaria.

and are the two main microsporidian parasites causing nosematosis in the honey bee . The aim of the present study is to investigate the presence of and in the area of Bulgaria. The 16S (SSU) rDNA gene region was chosen for analysis. A duplex PCR assay was performed on 108 honey bee samples from three different parts of the country (South, North and West Bulgaria). The results showed that the samples from the northern part of the country were with the highest prevalence (77.2%) for while those from the mountainous parts (the Rodopa Mountains, South Bulgaria) were with the lowest rate (13.9%). Infection with alone and co-infection were not detected in any samples. These findings suggest that is the dominant species in the Bulgarian honey bee. It is not known when the introduction of in Bulgaria has occurred, but as in the rest of the world, this species has become the dominant one in Bulgarian . In conclusion, this is the first report for molecular detection of infection of honey bee in Bulgaria. The results showed that is the main species in Bulgaria.