HONEY BEES PROVIDE CRITICAL POLLINATION SERVICES, BUT MULTIPLE CHALLENGES TO BEE HEALTH HAVE LED TO SERIOUS THREATS TO AGRICULTURAL POLLINATION DEMANDS. ONE OF THE LEADING CAUSES OF COLONY DEATH IS VIRUSES: HONEY BEES ARE COMMONLY INFECTED WITH SEVERAL DEVASTATING VIRUSES, INCLUDING ISRAELI ACUTE PARALYSIS VIRUS (IAPV). DESPITE THE IMPORTANCE OF VIRUSES TO BEE HEALTH, WE LACK AN UNDERSTANDING OF PHENOTYPIC EFFECTS OF VIRUSES ON BEES, THEIR TRANSMISSION, AND THUS HOW THEY ACTUALLY CAUSE COLONY FAILURE. A BETTER UNDERSTANDING OF VIRAL EFFECTS IS CRITICAL TO MORE EFFECTIVE MANAGEMENT AGAINST THESE DISEASES.WE PROPOSE A HIGHLY INTEGRATIVE PROJECT TO COMPREHENSIVELY INVESTIGATE HOW HONEY BEE VIRUSES AFFECT PHENOTYPES AT MULTIPLE LEVELS: GENOMIC, PHYSIOLOGICAL, AND BEHAVIORAL. OUR RESEARCH APPROACH IS GUIDED BY EVOLUTIONARY BIOLOGY -- WE WILL TEST THE HYPOTHESIS THAT THERE IS A BALANCING ACT BETWEEN ADAPTIVE HOST BEHAVIORAL RESPONSES TO REDUCE PATHOGEN TRANSMISSION AND VIRUS MANIPULATION OF BEE PHYSIOLOGY AND BEHAVIOR TO INCREASE THEIR OWN TRANSMISSION. TO ACCOMPLISH THIS, WE WILL EXPERIMENTALLY INFECT BEES WITH IAPV AND EXAMINE VIRUS TRANSMISSION DURING INTRA-HIVE AND EXTRA-HIVE BEHAVIOR. IN ADDITION, WE WILL DELVE INTO THE GENE EXPRESSION, HORMONAL, AND NUTRITIONAL IMPACTS OF IAPV INFECTION AND HOW THESE MECHANISMS CAUSE VIRUS-INDUCED SHIFTS IN BEHAVIOR.BECAUSE IAPV IS ASSOCIATED WITH OTHER CHALLENGES, NOTABLY VARROA MITE INFESTATION, THESE SHIFTS HAVE THE POTENTIAL TO SPREAD MULTIPLE PATHOGENS, NOT JUST IAPV ALONE. THUS, THE RESULTING DEEPER UNDERSTANDING OF HOW AND WHY VIRUSES AFFECT BEE PHENOTYPES WILL CONTRIBUTE TO THE BROAD KNOWLEDGE BASE NEEDED TO OVERCOME CHALLENGES TO BEE HEALTH.