DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Drippy gill
HOST: Mushroom
Drippy gill is characterized by small dark spots on gills with drops of bacterial ooze at the centers. Severe infection results in slimy areas and collapse of gills.

Drippy gill | Mushroom
DISEASE: Drippy gill
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas agarici
SOURCE: J. Young
DISEASE: Drippy gill
HOST: Mushroom
Close-up of infected gills with bacterial ooze.

Drippy gill | Mushroom
DISEASE: Drippy gill
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas agarici
SOURCE: J. Young
DISEASE: Drippy gill
HOST: Mushroom
Another view of small, dark spots on gills.

Drippy gill | Mushroom
DISEASE: Drippy gill
HOST: Mushroom (Agaricus campestris)
PATHOGEN: Pseudomonas agarici
SOURCE: J. Young
DISEASE: Periwinkle wilt
HOST: Periwinkle
Infected plants with stunting and sparse foliage (center and right).

Periwinkle wilt | Periwinkle
DISEASE: Periwinkle wilt
HOST: Periwinkle (Vinca sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: R. McCoy, M. Davis
DISEASE: Periwinkle wilt
HOST: Periwinkle
Draeculacephala minerva, leafhopper vector of Xylella fastidiosa on plants such as periwinkle and watercress.

Periwinkle wilt | Periwinkle
DISEASE: Periwinkle wilt
HOST: Periwinkle (Vinca sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, A. Purcell, M. Davis