OUR PROJECT ADDRESSES SEVERAL OF THE PRIORITIES OF THE PROGRAM AREA BY PROPOSING RESEARCH THAT ADDRESSES THE FACTORS INFLUENCING POLLINATOR HEALTH BY DEVELOPING AND EVALUATING INNOVATIVE TOOLS AND MANAGEMENT PRACTICES. THE ULTIMATE GOAL OF OUR THREE-YEAR PROJECT IS TO HELP THE US BEEKEEPING INDUSTRY BY IMPROVING THE HEALTH OF THE EUROPEAN HONEY BEE APIS MELLIFERA. A NASCENT ECTOPARASITIC MITE, VARROA DESTRUCTOR, AND THE DEFORMED WING VIRUS (DWV) AND RELATED VIRUSES (TOGETHER, DWV-LIKE VIRUSES) THEY VECTOR, ARE POSSIBLY THE GREATEST THREAT TO THE BEEKEEPING INDUSTRY, AND THUS AMERICAN'S FOOD SECURITY. RECENT INSIGHTS FROM OUR RESEARCH GROUP HAVE REEXAMINED HOW VARROA MITES VECTOR AND TRANSMIT DWVS TO HONEY BEES, AND REVEALED HOW VARROA-MEDIATED VECTORING MAY HAVE SELECTED FOR GENETICALLY DIVERSE AND VIRULENCE POPULATIONS OF DWV-LIKE VIRUSES OBSERVED IN US HONEY BEES. HIGH DIVERSITY FROM MANY RECOMBINANT GENETIC VARIANTS RENDER ANTI-DWV RNAI-BASED THERAPEUTICS INEFFECTIVE. THE INNOVATIVE BASIC RESEARCH OF OUR PROJECT WILL EMPLOY AND MODIFY AN INNOVATIVE CLONAL CDNA-BASED VIRUS VECTOR FOR DWV-LIKE VIRUSES TO ELUCIDATE THE MECHANISMS OF VARROA-MEDIATED VECTORING THAT CAUSE THE HIGH GENETIC DIVERSITY AND VIRULENCE OF DWV-LIKE VIRUSES OBSERVED IN US HONEY BEES. ALSO, OUR RESEARCH WILL EVALUATE IPM STRATEGIES EMPLOYED BY BEEKEEPERS TO CONTROL VARROA MITES FOR THEIR EFFECTS ON THE GENETIC DIVERSITY AND VIRULENCE OF DWV-LIKE VIRUSES. LASTLY, WE WILL DESIGN AND TEST AN INNOVATIVE, CLONAL CDNA-BASED DWV-LIKE VIRUS VECTORS HAVING VARROA MRNA INSERTS FOR RNAI KNOCKDOWN OF ESSENTIAL LIFE PROCESSES OF MITES. THIS SYSTEM WILL BE FREE OF ISSUES PLAGUING PAST RNAI-BASED CONTROLS.