DISEASE: Apple proliferation
HOST: Apple
Spring form of the adult black-veined psyllid, Cacopsylla melanoneura, a vector of apple proliferation. In winter, adults are more greenish in color.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica)
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Apple proliferation
HOST: Apple
Typical apple proliferation symptom of witches'-broom resulting from suppression of apical dominance and growth of dormant axillary buds. Branches are not usually bent down as shown here.

Apple proliferation | Apple
DISEASE: Apple proliferation
HOST: Apple (Malus domestica)
PATHOGEN: 'Candidatus Phytoplasma mali'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: M. Wolf, W. Schweigkofler
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon)
The term "black pit" refers to black lesions on fruit, which may be specks or large, sunken pits as seen here. They also may be light tan, later becoming reddish brown to black.

Bacterial blast and black pit | Citrus (Lemon)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Menge
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Lesions are necrotic and circular to angular. Some have yellowish halos. Older lesions become brown and dry.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Ooze from lesion on celery leaf.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: R. Raid
DISEASE: Bacterial blight (Brown stem)
HOST: Celery
Characteristic brown discoloration of petioles, which is more evident on inside of petiole close to the crown. Parenchyma tissues are firm and brown.

Bacterial blight (Brown stem) | Celery
DISEASE: Bacterial blight (Brown stem)
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Pernezny
DISEASE: Bacterial leaf spot
HOST: Celery
Leaves with typical symptoms of rusty brown lesions with greasy appearance.

Bacterial leaf spot | Celery
DISEASE: Bacterial leaf spot
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas syringae pv. apii
SOURCE: R. Gilbertson
DISEASE: Bacterial leaf spot
HOST: Celery
Celery leaves with rusty brown lesions and some yellowing at leaf tips.

Bacterial leaf spot | Celery
DISEASE: Bacterial leaf spot
HOST: Celery (Apium graveolens)
PATHOGEN: Pseudomonas syringae pv. apii
SOURCE: S. Koike