The genus Xylophilus is a Gram-negative betaproteobacteria following the reclassification of Xanthomonas ampelina, which comprises a single species, Xylophilus ampelinus, and has received considerable investigative attention. However, the available data on X. ampelinus remain limited, suggesting a potential underestimation of its occurrence. Additionally, a novel bacterial species, Xylophilus rhododendri, is proposed based on comprehensive taxonomic analyses. X. ampelinus is recognized as a regulated quarantine A2 organism by the EPPO, causing bacterial blight exclusively on the grapevine (Vitis vinifera), its sole known host. The disease predominantly affects temperate Mediterranean regions and South Africa, with the bacterium acting as a systemic pathogen that targets xylem tissues. Transmission primarily occurs through infected propagating material and epiphytic bacteria entering wounds, with no significant insect vectors identified. The EPPO protocol outlines a multistep detection approach for X. ampelinus, including screening tests employing immunofluorescence, enzyme-linked immunosorbent assay, conventional and real-time polymerase chain reaction, and fatty acid profiling. Chemical control options are limited, which emphasizes the importance of screening propagating materials for the presence of pathogens. Early and reliable detection coupled with rapid response measures is essential for mitigating the spread and impact of this pest. Preventive measures, such as disinfection of pruning tools and use of pathogen-free materials, are critical components of disease management strategies.