The
Citrus stubborn disease is a plant disease affecting species in the genus
Citrus.
Spiroplasma citri, a Mollicute bacterium species, is the causative agent of the disease. It is present in the phloem of the affected plant and transmitted by several leafhoppers including
Circulifer tenellus (beet leafhopper) and
Scaphytopius nitridus in citrus-growing regions of California and Arizona and
Circulifer haematoceps in the Mediterranean region.