Incubation Period of Aster-Yellows Virus

Strains of Myzus Persicae (sulz.) Active and Inactive with Respect to Virus Transmission

“…Individual variation in ability to transmit was first recognized by Storey (1932) in the leafhopper, Cicadulina mbila. This characteristic has since been recognized for other leafhopper species (Black 1943;Kunkel 1951;Maramorosch 1953), but the author is aware of only one attempt (Bawden and Kassanis 1947) to apply the findings of Storey to aphid vectors of plant viruses. These workers suggested "that occasional individual M. persicae or other potato aphis may be vectors although the bulk of such species are not" vectors of potato virus C. Their experiments with M. persicae, collected from many different sources and hosts, and other species of aphids, failed to support this hypothesis.…”

Region and Field Level Distributions of Aster Yellows Phytoplasma in Small Grain Crops

“…The disease development pattern likely resulted from either the late arrival of infested leafhopper vectors migrating into the agroecosystem from more southerly locations, or from locally emerging leafhopper populations feeding on AYpinfested perennial host plants and then becoming infective following an insect incubation period. A minimum incubation period in noninfected, locally emerging leafhoppers can range from 11 to 29 days before phytoplasma are transmitted in sufficient quantities to cause disease in plants (26). Migrating leafhoppers are known to leave crops in southern states when crop conditions deteriorate and warm air flows support flights to northern areas (8,30).…”