Prevalence and distribution of honey bee pests and pathogens in Uruguay

Here, we present the first honey bee pest and pathogen epidemiological study in Uruguay, as an attempt to increase the information about South American honey bee health status. Varroa destructor appeared to be widely distributed in the country, showing a prevalence of 75.7% in autumn. A third of affected colonies showed infestation levels above irreversible damage threshold (4%) and presented a 6-fold increased risk of being infected by deformed wing virus. Acute bee paralysis virus, black queen cell virus, and sacbrood virus were also detected, while Kashmir bee virus and Israeli acute paralysis virus were not. Nosema ceranae was the only detected microsporidium, suggesting the absence or extremely low prevalence of Nosema apis. No significant difference in pathogen distribution was observed between Africanized or European colonies. In conclusion, the main honey bee pathogens have been detected in Uruguay, showing a similar prevalence to those detected in Northern hemisphere countries, while no distribution differences were observed in Africanized or European bees. These multiple infections reflect the fragile balance of bee health worldwide.