DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Australian citrus dieback
HOST: Citrus (Lime)
Severe decline, a late stage of disease. The disease spreads slowly in mature trees, progressing faster in young trees.

Australian citrus dieback | Citrus (Lime)
DISEASE: Australian citrus dieback
HOST: Citrus (Lime) (Citrus sp.)
PATHOGEN: 'Candidatus Phytoplasma australiense'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: P. Broadbent
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lime)
Characteristic symptoms of brownish black lesions on twigs and leaves (blast), starting with infection of petioles. Black pit refers to brown to black sunken spots on fruit, 5 to 20 mm in diameter.

Bacterial blast and black pit | Citrus (Lime)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lime) (Citrus sp.)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: P. Broadbent
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown)
Leaf with flat, spreading lesions.

Bacterial leaf spot | Citrus (sp. unknown)
DISEASE: Bacterial leaf spot
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xanthomonas alfalfae subsp. citrumelonis
PATHOGEN SYNONYM: Xanthomonas alfalfae subsp. citrumelo
SOURCE: J. H. Graham
DISEASE: Bacterial leaf spot
HOST: Pellionia
Leaves with dry, irregularly shaped lesions with corky, raised borders on upper surface.

Bacterial leaf spot | Pellionia
DISEASE: Bacterial leaf spot
HOST: Pellionia (Pellionia sp.)
PATHOGEN: Xanthomonas campestris
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Pellionia
Leaf lesions are irregular, corky, and slightly raised on lower leaf surfaces. Lesions may fall out, leaving a shot-hole appearance.

Bacterial leaf spot | Pellionia
DISEASE: Bacterial leaf spot
HOST: Pellionia (Pellionia sp.)
PATHOGEN: Xanthomonas campestris
SOURCE: H. Schwartz
DISEASE: Citrus canker
HOST: Citrus (sp. unknown)
Fruit with erumpent, corky lesions with collapsed centers surrounded by blackish halos.

Citrus canker | Citrus (sp. unknown)
DISEASE: Citrus canker
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: J. Young
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown)
Citrus psyllid (Diaphorina citri), a vector of 'Candidatus Liberibacter asiaticus', the cause of citrus greening, feeding on green twig.

Citrus greening (Huanglongbing) | Citrus (sp. unknown)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: C. Jacobson
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown)
Citrus psyllid (Diaphorina citri), a vector of 'Candidatus Liberibacter asiaticus', the cause of citrus greening.

Citrus greening (Huanglongbing) | Citrus (sp. unknown)
DISEASE: Citrus greening (Huanglongbing)
HOST: Citrus (sp. unknown) (Citrus sp.)
PATHOGEN: 'Candidatus Liberibacter asiaticus'
PATHOGEN SYNONYM: Candidatus Liberobacter asiaticus
SOURCE: C. Jacobson