Technical Abstract: Xylella fastidiosa is a xylem-limited bacterium that causes several scorch diseases in important crops, such as Pierce’s disease of grape. Bacteria form a dense biofilm on the foregut cuticle of the glassy-winged sharpshooter, H. vitripennis, and other xylem-feeding vectors. Bacteria are inoculated directly from sites in the foregut into a host plant during sharpshooter feeding (i.e. probing of the mouthparts, stylets, into the plant). However, despite nearly 70 years of research, no one has yet definitively associated specific sharpshooter stylet probing behaviors with such inoculation. The most rigorous method to identify sharpshooter feeding behaviors is electrical penetration graph (EPG) monitoring. The purpose of this chapter is to review progress made towards identifying those feeding behaviors leading to X. fastidiosa transmission. Specific objectives are to: 1) summarize work of the last ten years to identify and define EPG waveforms representing feeding behaviors of sharpshooters, 2) describe a model for xylem cell acceptance behaviors during feeding, and 3) present the Salivation-Egestion Hypothesis for X. fastidiosa inoculation, in which salivation combined with egestion [outward fluid flow] carries bacteria into the xylem. Understanding the inoculation mechanism will aid development of grape varieties resistant to inoculation of X. fastidiosa by sharpshooter vectors.