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 fasciation (Leafy gall)
HOST: Begonia
Leafy gall on stem.

Bacterial fasciation (Leafy gall) | Begonia
DISEASE: Bacterial fasciation (Leafy gall)
HOST: Begonia (Begonia sp.)
PATHOGEN: Rhodococcus fascians
SOURCE: M. Geesteranus, J. van der Wolf
DISEASE: Bacterial leaf spot (Blight)
HOST: Begonia
Initial symptoms appear as small, blisterlike lesions. As lesions age, they enlarge, producing broad patches of necrotic leaf tissue.

Bacterial leaf spot (Blight) | Begonia
DISEASE: Bacterial leaf spot (Blight)
HOST: Begonia (Begonia sp.)
PATHOGEN: Xanthomonas axonopodis pv. begoniae
PATHOGEN SYNONYM: Xanthomonas campestris pv. begoniae
SOURCE: APS
DISEASE: Bacterial leaf spot (Blight)
HOST: Begonia
Advanced stage of disease with dark, large necrotic areas on leaves and interveinal chlorosis.

Bacterial leaf spot (Blight) | Begonia
DISEASE: Bacterial leaf spot (Blight)
HOST: Begonia (Begonia sp.)
PATHOGEN: Xanthomonas axonopodis pv. begoniae
PATHOGEN SYNONYM: Xanthomonas campestris pv. begoniae
SOURCE: APS
DISEASE: Blister spot
HOST: Apple
Fruit with water-soaked spots.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blister spot
HOST: Apple
Water-soaked blister spots on leaves of blighted twig.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Blossom blast
HOST: Apple
Many dead, shriveled flowers and young shoots. It differs from fire blight, with infections being relatively localized with the appearance of being "blasted".

Blossom blast | Apple
DISEASE: Blossom blast
HOST: Apple (Malus domestica)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: M. Schroth