Characterizing Xylella Fastidiosa Pathogen Dynamics on Diverse Small Fruit Farms

Global agriculture has been threatened for over a century due to the emergence of the plant pathogenic bacteria Xylella fastidiosa (Lysobacterales: Lysobacteraceae) (Xf). Xf comprises five main subspecies and induces severe physiological symptoms in a diverse set of host plant species by limiting xylem function. Xylem-feeding insect vectors can transmit Xf to host plants, spreading disease and reducing fruit yield. Here I studied Xf prevalence on small fruit farms to determine Xf host plant and vector infective status to the Xf subspecies level. I detected Xf in 28 host plants in South Carolina containing either Xf subspecies fastidiosa or multiplex. I also found leafhoppers Cuerna costalis (Hemiptera: Cicadellidae), Graphocephala coccinea (Hemiptera: Cicadellidae), Graphocephala versuta (Hemiptera: Cicadellidae), Homalodisca vitripennis (Hemiptera: Cicadellidae), Jikradia olitoria (Hemiptera: Cicadellidae), and Oncometopia orbona (Hemiptera: Cicadellidae) to contain Xf. By investigating Xf and subspecies within plants and vectors, we were able to determine that Xf could pose a risk on small fruit crop farms, and hope to promote informed grower decision-making regarding plant health status based on our findings.