Aster leafhopper

Important vegetables that serve as hosts include lettuce, celery, carrots, endice, and parsnip. During early to mid summer, as winter grasses senesce, newly emerged adult aster leafhoppers move to these crops, as well as more succulent spring grain, weed hosts, and susceptible vegetable, ornamental and field crops. Common weed hosts for aster yellows include: thistle, fleabane, wild lettuce, sow thistle, chicory, wild carrot, galinsoga, dandelion, plantain, cinquefoil and others. Susceptible flowers include aster, chrysanthemum, cockscomb, coreopsis, cosmos, daisy, dianthus, echinacea (coneflower), gladiolus, marigold, petunia, and phlox. Overall, 150 species of plants in 40 different families have been recorded as hosts of aster yellows vectored by the aster leafhopper.
To acquire and transmit the aster yellows mycoplasma, the aster leafhopper must feed for a prolonged period (at least two hours) on an infected host (either locally or in a southern state). Next, the pathogen must incubate within the leafhopper for about 3 weeks before it can be transmitted to another plant. Because of the extensive incubation period, the disease is rarely spread from plant to plant within a commercial field. Thus, the primary method for transmission of aster yellows to a host in Minnesota is by the migrant adults already carrying the pathogen.