Abstract
In recent years, increased deforestation and replacement of areas intended for intensive cultivation have caused pathogens and parasites of Apis mellifera bees to emerge in regions where they had not previously been reported. Such is the case of the advancement of Ascosphaera apis, a fungus that causes a drop in colonies’ bee larvae population and great economic losses to beekeeping activity during severe cases. In northern Argentina, few studies have focused on this important entomopathogen. This is the first study on A. apis isolated from commercial pollen in Entre Ríos, Jujuy, and Misiones provinces, where its prevalence in bee colonies has not been reported. We identified this entomopathogen using macroscopic, microscopic, and molecular analyses, focusing on its botanical origin as a possible transmission route. We found the pathogenicity of each strain in A. mellifera bees to below 30%. The results of this study contribute to the promotion of sanitary measures that may reduce this disease’s progression in local apiaries.