Leaves of infected plants are reddish purple. Infected plants often bolt prematurely. Aster Yellows Phytoplasma. Leaves of infected plants are twisted, stunted, and yellow. Leaflets may be reduced to short scales.
Infected plants show increased lateral rootlet development.
The beet leafhopper transmitted viresence agent is transmitted by the beet leafhopper, Circulifer tenellus. Aster yellows phytoplasma is transmitted by several species of leafhoppers. Both phytoplasmas have wide host ranges. The level of infection in carrot fields is dependent on the population of vectors. The Regents of the University of California.