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: Dogwood stunt
HOST: Dogwood
Diseased plant with small leaves (left).

Dogwood stunt | Dogwood
DISEASE: Dogwood stunt
HOST: Dogwood (Cornus sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Sinclair
DISEASE: Petal blight
HOST: Orchid
Flower petals of Vanda orchid with necrotic spots.

Petal blight | Orchid
DISEASE: Petal blight
HOST: Orchid (Vanda sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: A. Alvarez