Plant viruses are typically not afforded the luxury of a mobile host to facilitate their propagation and thus they rely on insect vectors for efficient transmission. There is a dynamic interplay between the plant host, the virus and the insect vector and it is imperative to understand all facets of this synergistic system. My work is focused on Poleroviruses which are transmitted exclusively in a circulative manner by sap sucking aphids. The virion does not infect, replicate or uncoat within insect tissues meaning that all of the information necessary for transmission can be pinpointed back to the capsid protein components. My objective is to determine the exact components of the viral particle that enable transmission and how it moves through the aphid between infected crops by using a variety of structural and cell biology methods. The proposed work will produce novel insights into the architectural organization of luteovirid capsids and define the specific cellular compartments transversed by these viruses during viral acquisition and transmission by aphids. This information will inform novel crop control strategies to disrupt viral transmission. Given the similarities in the circulative transport pathway for viral and bacterial phytopathogens, creating a toolkit to visualize protein interactions in insect vectors can be readily applied to understanding vector pathogen interactions and viral transmission in other pathosystems.