WHITEFLIES CAUSE BILLIONS OF DOLLARS IN CROP LOSSES ANNUALLY THROUGH DIRECT DAMAGE AND TRANSMISSION OF PLANT VIRUSES. SUSTAINED FEEDING BY WHITEFLIES DEPENDS ON SECRETION OF SALIVA CONTAINING COMPOUNDS THAT SUPPRESS PLANT DEFENSES, WHICH ARE KNOWN AS EFFECTORS. HOWEVER, LITTLE PROGRESS HAS BEEN MADE ON DISCOVERY AND CHARACTERIZATION OF EFFECTORS IN WHITEFLIES DESPITE THE POTENTIAL FOR THIS KNOWLEDGE TO IMPROVE OUR ABILITY TO MANAGE THIS DEVASTATING PEST. ONE OF THE MANY UNKNOWNS INVOLVES THE CONTRIBUTION OF THE INSECT'S MICROBIOME TOWARD THE COMPOSITION OF EFFECTORS IN SALIVA. WHITEFLIES HOST BACTERIA THAT OFTEN ENHANCE PERFORMANCE BY PROVIDING NUTRIENTS AND AUGMENTING PHYSIOLOGICAL PROCESSES. THIS, IN TURN, LEADS TO MORE WHITEFLIES IN CROP SYSTEMS AND ADJACENT HABITATS. USING A UNIQUE SYSTEM CONSISTING OF TWO LINES OF AN INVASIVE WHITEFLY THAT DIFFER ONLY IN THEIR MICROBE ASSOCIATES, WE FOUND EVIDENCE THAT THE BENEFITS OF HOSTING PARTICULAR MICROBES CAN INCLUDE MORE EFFECTIVE SUPPRESSION OF PLANT DEFENSES. WE HYPOTHESIZE THAT THIS IS MEDIATED BY THE EFFECTS OF MICROBE ASSOCIATES ON THE SALIVA THAT WHITEFLIES RELEASE INTO HOST PLANTS DURING FEEDING. TO TEST THIS HYPOTHESIS, WE WILL DETERMINE WHAT COMPOUNDS AND PROTEINS ARE PRESENT IN THE WHITEFLY SALIVA AND HOW THEY DIFFER DEPENDING ON THE MICROBES PRESENT INSIDE THE WHITEFLY BODY. USING PUBLICLY AVAILABLE RESOURCES ON INSECT GENETICS, WE WILL USE OUR DATA TO UNDERSTAND HOW WHITEFLY SALIVA COMPONENTS RELATE TO THOSE FOUND IN OTHER INSECTS. WE WILL ALSO USE NEW TECHNIQUES TO BLOCK PRODUCTION OF SPECIFIC SALIVA EFFECTORS IN LIVE WHITEFLIES, THEN MEASURE THE IMPACT OF EFFECTOR ABSENCE ON THE ABILITY OF WHITEFLIES TO FEED ON PLANTS. THIS APPROACH WILL HELP RESEARCHERS TO UNDERSTAND HOW WHITEFLIES AND RELATED INSECTS ARE ABLE TO OVERCOME DEFENSES IN PLANTS TO CAUSE CROP DAMAGE AND TRANSMIT PATHOGENS. OUR PROJECT ACTIVITIES DIRECTLY SUPPORT PRIORITIES LAID OUT IN THE RECENT FARM BILLBY PROVIDING INFORMATION THAT WILL IMPROVE OUR UNDERSTANDING OF MECHANISMS OFHOST EXPLOITATION BY ANINVASIVE PEST THAT THREATENS AGRICULTURAL SUSTAINABILITY WORLDWIDE.