** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** ARTHROPODS PLAY MAJOR ROLES IN AGRICULTURAL PRODUCTION BY ACTING AS BIOLOGICAL CONTROL AGENTS OR CROP PESTS. MOST ARTHROPODS ALSO HOST MATERNALLY INHERITED, INTRACELLULAR BACTERIAL SYMBIONTS THAT CAN PROVIDE THEIR HOST WITH REQUIRED NUTRIENTS, PROTECT HOSTS FROM IMPORTANT NATURAL ENEMIES, OR MANIPULATE THE OUTCOMES OF HOST REPRODUCTION. HIGH TEMPERATURES CAN DESTABILIZE THESE SYMBIOSES BY REDUCING TRANSMISSION EFFICACY AND PREVENTING THE SYMBIONT FROM MODIFYING THEIR HOST. THE PREDICTED INCREASE IN GLOBAL TEMPERATURES HAS UNCLEAR CONSEQUENCES FOR HERITABLE SYMBIONTS AND THEIR ARTHROPOD HOSTS. SPIDERS ARE AN IMPORTANT BUT UNDERSTUDIED GROUP OF GENERALIST PREDATORS THAT OFTEN HARBOR COMPLEX HERITABLE SYMBIONT COMMUNITIES AND ARE EMERGING MODELS FOR STUDYING HERITABLE SYMBIONTS. THIS PROJECT WILL USE FIELD SURVEYS, LABORATORY-BASED EXPERIMENTS EXPOSING SPIDERS TO CURRENT AND PREDICTED HIGH TEMPERATURES, AND GENOMIC ANALYSES TO ADDRESS THREE QUESTIONS: 1) DOES CLIMATE SHAPE SYMBIONT FREQUENCY IN US SPIDER POPULATIONS? 2) DOES TEMPERATURE STRESS DESTABILIZE HERITABLE SYMBIOSES? 3) DO SYMBIONT GENOMES ENCODE RESPONSES TO TEMPERATURE STRESS? RESULTS WILL REVEAL HOW CLIMATE INFLUENCES SPIDER SYMBIONTS AND WILL ESTABLISH A NEW SPIDER MODEL SYSTEM FOR STUDYING HERITABLE SYMBIOSES. THIS RESEARCH WILL FURTHER CHARACTERIZE THE ROLE OF SYMBIONTS IN ARTHROPOD BIOLOGY AND HOW CLIMATE CHANGE MIGHT AFFECT THESE WIDESPREAD SYMBIOSES. DATA FROM THIS PROJECT WILL BE MADE PUBLICLY AVAILABLE FOR POTENTIAL USE IN OTHER RESEARCH, INCLUDING DEVELOPING MODELS PREDICTING THE IMPACT OF CLIMATE CHANGE ON ARTHROPOD POPULATIONS AND THEIR HERITABLE SYMBIONTS. THIS PROJECT WILL ALSO GENERATE A HIGHLY TRAINED AND COMPETITIVE WORKFORCE THAT ARE WELL PREPARED TO ADDRESS EMERGING AGRICULTURAL CHALLENGES, INCLUDING AGRICULTURAL CLIMATE ADAPTATION, BY PROVIDING POSTDOCTORAL AND UNDERGRADUATE RESEARCH, MENTORSHIP, TEACHING, AND PROJECT MANAGEMENT TRAINING. IT WILL ALSO INCREASE SCIENTIFIC LITERACY IN THE GENERAL PUBLIC BY DEVELOPING AN EDUCATIONAL MODULE ON DNA SEQUENCING FOR UNDERGRADUATE AND HIGH SCHOOL STUDENTS. THIS MODULE WILL INCLUDE HANDS ON EXPERIENCE EXTRACTING DNA AND ANALYZING DNA SEQUENCING, COMMON TECHNIQUE EMPLOYED BY BIOLOGY LABS.