The development of beekeeping in Ecuador has generated the need to strengthen the bee health program. Research on the main pathogens responsible for diseases like nosemosis, which can severely impact bee health, is of special interest. This study aims to identify the Nosema apis and/or Nosema ceranae species infecting honey bee colonies located in the northern Andean region of Ecuador using multiplex PCR targeting the RNA polymerase II gene (RPB1), and the phylogenetic analysis of N. ceranae based on the 16 S rRNA gene sequences. Among the 164 honey bee samples collected from colonies in the provinces of Carchi, Imbabura, and Pichincha, the prevalence of Nosema apis and Nosema ceranae was 14.63% and 21.34%, respectively. Phylogenetic analysis showed that N. ceranae from Ecuador is closely related to the sequences from Argentina and Brazil. These findings provide the first molecular confirmation of N. ceranae in Ecuador and support the need for molecular monitoring of honey bee pathogens in the region.

The development of beekeeping in Ecuador has generated the need to strengthen the bee health program. Research on the main pathogens responsible for diseases like nosemosis, which can severely impact bee health, is of special interest. This study aims to detect and identify the Nosema apis and / or Nosema ceranae species affecting honeybee colonies located in the northern Sierra region of Ecuador through the amplification of RPB1 gene fragments by multiplex PCR and the phylogenetic analysis of N. ceranae based on the 16 S RNAr gene. Of the 164 honeybee samples collected from colonies located in the provinces of Carchi, Imbabura and Pichincha, N. apis was detected in 14.63% (24/164), and N. ceranae in 21.34% (35/164). Phylogenetic analysis showed that N. ceranae from Ecuador is closely related to the sequences from Argentina and Brazil. This study is the first in the country to report the presence of these two microsporidia species, being valuable for improving diagnostic capabilities.