Pierce's disease of grape

Definition

A lethal vascular wilt disease of grapevines (Vitis spp.) caused by the bacterium Xylella fastidiosa, transmitted exclusively by xylem-feeding hemipteran insects, especially sharpshooters (Cicadellinae) and spittlebugs (Cercopidae). The pathogen colonizes and occludes xylem vessels, inducing leaf scorch, fruit shrivel, and vine decline. The disease is endemic to the Americas and poses severe economic threats to viticulture; management hinges on vector suppression, host removal, and resistant rootstocks.

Etymology

Named after Newton B. Pierce (1856–1916), California state botanist who first described the disease in 1892.

Example

In California vineyards, the glassy-winged sharpshooter (Homalodisca vitripennis) is the principal vector; a single infected insect can inoculate multiple vines during probing, making this invasive species a priority target for area-wide vector management programs.

Synonyms

• PD
• Pierce's disease
• PDG

Related Terms

• Vector
• sharpshooter
• xylem-feeder
• Xylella fastidiosa
• leafhopper
• Glassy-winged sharpshooter
• plant disease ecology
• hemipteran vector

Usage Notes

The term properly includes "of grape" to distinguish it from other Xylella fastidiosa diseases (e.g., citrus variegated chlorosis, almond leaf scorch). In casual viticulture contexts, "Pierce's disease" alone is common, but this can obscure the vector-borne, multisystem nature of the pathogen. Specialists reserve "PD" for written shorthand and avoid it in public communication due to confusion with other grape disorders. The disease is not transmissible by grafting or seed; vector competence varies dramatically among cicadellid species, with some efficient vectors (e.g., Graphocephala atropunctata) and many incompetent ones.