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: Greening disease
HOST: Periwinkle
Healthy flower and infected flower.

Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
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
DISEASE: Periwinkle yellows
HOST: Periwinkle
Leaves with characteristic yellow and chlorotic appearance. Yellowing is first associated with veins.

Periwinkle yellows | Periwinkle
DISEASE: Periwinkle yellows
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis
DISEASE: Vinca virescence
HOST: Periwinkle
Diseased plants with virescence symptoms.

Vinca virescence | Periwinkle
DISEASE: Vinca virescence
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: B. Raju, M. Davis
DISEASE: Witches'-broom
HOST: Paulownia (Empress tree)
Witches'-broom of paulownia.

Witches'-broom | Paulownia (Empress tree)
DISEASE: Witches'-broom
HOST: Paulownia (Empress tree) (Paulownia tomentosa)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. Davis, M. Davis