BEES ARE CRUCIAL POLLINATORS WHO ARE BEINGEXPOSED TO HARMFUL AGRICULTURAL CHEMICALS (E.G. PESTICIDES AND FUNGICIDES) IN BOTH NECTAR AND POLLEN OF CROPS AND WILDFLOWERS. THESE CHEMICALS HAVE BROAD IMPACTS ON POLLINATOR HEALTH, BUT THEIR IMPACTS ON BEE AND PLANT MICROBIOMES REMAIN POORLY UNDERSTOOD. THE MICROBES FOUND IN BEE'S DIGESTIVE TRACT AND INSIDE FLOWERS ARE CRITICAL FOR CERTAIN ASPECTS OF BEE HEALTH (SUCH AS DIGESTION AND PROTECTION AGAINST PARASITES) AND CAN EVEN INFLUENCE THE WAY BEES INTERACT WITH PLANTS. IN AGRICULTURAL ECOSYSTEMS, PLANTS ARE OFTEN TREATED WITH MULTIPLE CHEMICALS, AND THERE IS A CRITICAL KNOWLEDGE GAP REGARDING HOW COMBINATIONS OF AGROCHEMICALS ALTER FLORAL AND BEE MICROBIAL COMMUNITIES IN WAYS THAT ARE MEANINGFUL TO EITHER PARTY. I WILL COMBINE LAB AND FIELD-BASED APPROACHES TO ASSESS WHETHER PESTICIDES, FUNGICIDES, AND THEIR COMBINATION ALTER 1) THE WILD BUMBLE BEE MICROBIOME 2) THE FLORAL MICROBIOME 3) PLANT-POLLINATOR INTERACTIONS AND 4) LANDSCAPE-LEVEL PATTERNS IN FLORAL MICROBES. TO ACCOMPLISH THIS, I WILL DOSE WILD-CAUGHT BUMBLE BEES AND TREAT FLORAL MICROBES WITH A COMMON PESTICIDE, FUNGICIDE, AND THEIR COMBINATION TO QUANTIFY CHANGES IN MICROBIAL COMMUNITIES. THEN, I WILL COMPARE HOW THE SAME CHEMICAL TREATMENTS AFFECT THE FLORAL MICROBIOME AND REPRODUCTIVE SUCCESS OF A PLANT COMMONLY FOUND IN AGRICULTURAL MARGINS, PENSTEMON. FINALLY, I WILL COMPARE FLORAL MICROBIAL COMMUNITIES IN PENSTEMON PLANTS SAMPLED ALONG A GRADIENT OF POTENTIAL EXPOSURE TO AGRICULTURAL CHEMICALS. THESE PLANTS ARE OFTEN RECOMMENDED AS PART OF POLLINATOR-FRIENDLY PLANTINGS IN AGRICULTURAL FIELDS AND URBAN ENVIRONMENTS, AND IT WILL BE INSIGHTFUL TO KNOW HOW THEIR MICROBIAL COMMUNITIES ARE ALTERED BY EXPOSURE TO AGRICULTURAL CHEMICALS. GIVEN RECENT UNDERSTANDING OF HOW IMPORTANT MICROBES ARE TO BOTH POLLINATOR HEALTH AND PLANT PRODUCTIVITY, UNDERSTANDING HOW AGRICULTURAL CHEMICAL COMPLEXITY CAN ALTER BEE-MICROBE-PLANT INTERACTIONS IS A PRESSING QUESTION FOR MAINTAINING HEALTHY POLLINATORS IN AGRICULTURAL ECOSYSTEMS.