BEES ARE ROUTINELY TRANSPORTED FOR CROP POLLINATION SERVICES, AND THEIR ASSOCIATED PARASITES AND PATHOGENS ARE CONSEQUENTLY CO-INTRODUCED INTO NOVEL ENVIRONMENTS. IMPORTANTLY, PATHOGENS HAVE BEEN ASSOCIATED WITH LOSSES OF SEVERAL AGRICULTURALLY IMPORTANT WILD AND MANAGED POLLINATORS. AGRICULTURALLY IMPORTANT POLLINATORS INCLUDING HONEY BEES, LEAFCUTTER BEES, AND MASON BEES CAN SUFFER FROM CHALKBROOD DISEASE, CAUSED BY SPECIES OF FUNGI WITHIN THE GENUS ASCOSPHAERA. CO- OCCURRENCE OF ASCOSPHAERA SPECIES IS PRESUMED COMMON IN BOTH MANAGED AND NATURAL POLLINATION SYSTEMS, AND RECENTLY INTRODUCED NON-NATIVE MASON BEES (OSMIA) FROM ASIA HAVE ALSO BROUGHT ALONG NOVEL SPECIES OF ASCOSPHAERA IN THE US, WHICH HAVE BEEN DETECTED IN NATIVE OSMIA. MY PROPOSED RESEARCH PROJECT FOR THIS POSTDOCTORAL FELLOWSHIP (WITH PRIMARY MENTOR SCOTT MCART OF CORNELL UNIVERSITY) SEEKS TO IDENTIFY CO-OCCURRING ASCOSPHAERA SPECIES IN MANAGED AND WILD OSMIA, DETERMINE THE PATHOGENICITY OF ASCOSPHAERA SPECIES AND THEIR INTERACTIONS INSIDE BEE NESTS, AND EVALUATE CONSEQUENCES OF ASCOSPHAERA CO-INFECTION FOR NATIVE AND INTRODUCED OSMIA. I WILL COLLECT OSMIA NESTS IN BOTH NATIVE AND NON-NATIVE MANAGED SYSTEMS, AND EMPLOY HIGH-THROUGHPUT SEQUENCING, FUNGAL CULTURING TECHNIQUES, AND LARVAL BIOASSAYS TO EVALUATE THE OUTCOMES OF ASCOSPHAERA CO-INFECTION ON NATIVE AND INTRODUCED MASON BEES. SINGLE-SPECIES PATHOGEN STUDIES HAVE BEEN CRUCIAL FOR GENERATING BEST MANAGEMENT PRACTICES (BMPS) FOR THE MOVEMENT AND TRADE OF POLLINATORS THAT SAFEGUARD POLLINATOR HEALTH. HOWEVER, A BETTER UNDERSTANDING OF NOVEL CO-INFECTION DYNAMICS AND DISEASE IN BEES COULD IMPROVE BMPS.