THE SOYBEAN APHID IS ONE OF THE MAIN PESTS OF SOYBEAN IN THE U.S, CAUSING EN ESTIMATED ECONOMIC IMPACT RANGING BETWEEN $2-5 BILLION EACH YEAR. CURRENT MANAGEMENT STRATEGIES BASED ON INSECTICIDES ARE NOT SUSTAINABLE, AND HOST PLANT RESISTANCE MAY HAVE LIMITED USE DUE TO THE FAST EVOLUTION OF APHID BIOTYPES. THUS, A BETTER UNDERSTANDING OF THE MOLECULAR MECHANISMS MEDIATING THIS PLANT-APHID INTERACTION IS NECESSARY TO DEVELOP ADDITIONAL MANAGEMENT APPROACHES.IT IS ACCEPTED THAT APHIDS USE SALIVARY EFFECTORS TO SUPPRESS PLANT DEFENSES AND INCREASE THEIR SUSCEPTIBILITY TO COLONIZATION. HOWEVER, NEITHER THE SALIVARY EFFECTORS OF THE SOYBEAN APHID NOR THE MECHANISMS THEY TRIGGER TO BLOCK SOYBEAN DEFENSES ARE KNOWN. WE HYPOTHESIZE THAT SOYBEAN APHIDS USE PROTEIN AND RNA SALIVARY EFFECTORS THAT INDUCE A PHYTOHORMONAL CROSSTALK TO BLOCK PLANT IMMUNITY. TO TEST THIS HYPOTHESIS WE WILL 1) DEVELOP A SCREENING TO IDENTIFY SALIVARY PROTEINS THAT INDUCE HORMONE SIGNALS THAT ANTAGONIZE DEFENSE RESPONSES; 2) SURVEY CHANGES IN THE PLANT SMALL RNA TRANSCRIPTOME AND THE PRESENCE OF RNAS THAT ACT AS SALIVARY EFFECTORS, AND THEIR PLANT TARGETS; AND 3) CHARACTERIZE THE SIGNALING EVENTS INDUCED BY PROTEIN AND RNA EFFECTORS TO BLOCK SOYBEAN DEFENSES.WE EXPECT TO PRODUCE ADVANCES IN FUNDAMENTAL KNOWLEDGE THAT MAY LEAD TO THE DEVELOPMENT OF NOVEL MANAGEMENT STRATEGIES BY IDENTIFYING INSECT PROTEINS AND RNAS THAT CAN BE TARGETED THROUGH EMERGING IN PLANTA STRATEGIES OF INSECT CONTROL.