Microsporidia: An Emerging Threat to Bumblebees?

Area of Science:

• Ecology
• Pathogen Biology
• Conservation Biology

Background:

• Microsporidia are emerging infectious diseases (EIDs) that impact bumblebee populations.
• Commercial bumblebees and managed honey bees are potential sources of pathogen spillover.
• Declining bumblebee populations may increase susceptibility to microsporidia due to reduced genetic diversity.

Purpose of the Study:

• To investigate the drivers of emerging infectious diseases in bumblebees.
• To understand the role of managed bees in microsporidia spillover.
• To identify the causes behind increased microsporidia prevalence in North America.

Main Methods:

• Review of existing data on microsporidia prevalence and bumblebee population dynamics.
• Analysis of potential pathogen spillover pathways from managed bees.
• Call for phylogenomic studies to determine microsporidia population structure.

Main Results:

• Strong evidence suggests recent increases in Nosema bombi prevalence in North America.
• Definitive data on microsporidia spillover is lacking, hindering cause identification.
• The precise sources and pathways of microsporidia transmission remain unclear.

Conclusions:

• Urgent need for phylogenomic studies to understand global microsporidia population structure in bumblebees.
• Identifying pathogen sources is crucial for managing current and future epidemics.
• Further research is required to mitigate the impact of microsporidia on bumblebee health and conservation.