Plant pathogens have evolved numerous strategies that enable their movement from plant to plant. Phytopathogens use a great variety of insect species for transmission to plants, and insect transmission has evolved multiple times independently, particularly for phloem-inhabiting bacteria. Recent studies have advanced our understanding about the mechanisms of physical association between plant pathogenic bacteria and insect vectors. Furthermore, recent evidence shows that the transmission of plant pathogens goes beyond a physical association with the insect, and involves active modulation of plant processes by the bacteria to promote insect herbivore attraction, colonization and pathogen transmission.