INSECT POLLINATION IS VITAL FOR FOOD PRODUCTION AND CONTRIBUTES BILLIONS OF DOLLARS ANNUALLY TO THE UNITED STATES ECONOMY. WHILE MOST POLLINATION-RELATED RESEARCH CONCERNS THE IMPORTED EUROPEAN HONEY BEE (APIS MELLIFERA), NATIVE INSECTS ARE ALSO MAJOR POLLINATORS IN BOTH AGRICULTURAL AND NATURAL ECOSYSTEMS. OF THESE, BUMBLE BEES ARE PARTICULARLY IMPORTANT TO STUDY; CROPS SUCH AS TOMATOES AND BLUEBERRIES BENEFIT SPECIFICALLY FROM BUMBLE BEE POLLINATION, AND POPULATIONS OF A NUMBER OF BUMBLE BEE SPECIES ARE DECLINING, DUE TO THE INTERPLAY OF MULTIPLE ENVIRONMENTAL STRESSORS. IN NORTH AMERICA, THE SPECIES BOMBUS IMPATIENS IS ALSO REARED COMMERCIALLY FOR CROP POLLINATION. THIS PROJECT ADDRESSES THE ROLE OF GUT BACTERIA IN BUMBLE BEE HEALTH AND RESILIENCE TO STRESSORS, WITH A FOCUS ON B. IMPATIENS. B. IMPATIENS AND OTHER BUMBLE BEES HAVE RECENTLY BEEN SHOWN TO HOST A SPECIFIC COMMUNITY OF BACTERIA IN THEIR DIGESTIVE TRACT, YET WE HAVE A LIMITED UNDERSTANDING OF HOW THESE BACTERIA INTERACTWITH THEIR HOSTS AND THE ENVIRONMENT.BOTH BOMBUS IMPATIENSAND BEE GUT BACTERIA CAN BE RAISED IN THE LABORATORY, FACILITATING EXPERIMENTS UNDER CONTROLLED CONDITIONS. USING A PANEL OF GUT BACTERIAL SPECIES AND STRAINS ORIGINALLY ISOLATED FROM A VARIETY OF BUMBLE BEE SPECIES, GROWTH WILL BE MEASURED IN RESPONSE TO STRESSORS THAT BEES EXPERIENCE IN THE ENVIRONMENT, INCLUDING HEAT STRESS, PATHOGENS, AND THE COMMON HERBICIDE GLYPHOSATE. SUBSEQUENTLY, B. IMPATIENS WILL BE USED TO TEST THE EFFECTS OF THESE STRESSORS ON B. IMPATIENS GUT BACTERIA AND HEALTH. EXISTING GENOME SEQUENCES FOR ALL OF THE GUT BACTERIA INVOLVED WILL BE EXAMINED TO UNCOVER THE MOLECULAR-LEVEL MECHANISMS OF BACTERIAL RESPONSES TO STRESS AND INTERACTIONS WITH THEIR HOSTS. THIS WORK WILL IMPROVE OUR UNDERSTANDING OF WHY SOME BUMBLE BEE POPULATIONS ARE IN DECLINE, AND MAY YIELD PRODUCTS, SUCH AS PROBIOTIC GUT BACTERIAL STRAINS, THAT COULD BE USED TO IMPROVE THE HEALTH AND POLLINATION EFFECTIVENESS OF MANAGED BUMBLE BEES.