VIEW ARTICLE

Vector Relations

Evidence for Lack of Propagation of Potato Leaf Roll Virus in its Aphid Vector, Myzus persicae. F. Eskandari, Visiting associate professor, Division of Entomology and Parasitology, University of California, Berkeley CA 94720; E. S. Sylvester(2), and J. Richardson(3). (2)(3)Professor of entomology, and staff research associate, respectively, Division of Entomology and Parasitology, University of California, Berkeley CA 94720. Phytopathology 69:45-47. Accepted for publication 18 July 1978. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-45.

Two isolates of potato leaf roll virus (PLRV) were used in serial passage tests with the green peach aphid, Myzus persicae. Initial characterization of the transmission pattern indicated that at 25 C individual first instar larvae efficiently (92%) acquired and transmitted virus from infected Physalis floridana. When transferred to a sequence of P. floridana test seedlings, infective single aphids lived 18–24 days. After a 30–49 hr median latent period, they inoculated an average of six to eight seedlings and remained infective for an average of 9–11 days. These estimates varied somewhat with the length of the acquisition access period. Approximately 14% of late instar larvae injected with hemolymph from infective aphids transmitted PLRV. Injected insects survived about 16 days and inoculated an average of slightly more than one plant per insect after a median latent period of approximately 85 hr. They remained infective for approximately 5 days. In a series of serial passage trials, infectivity of aphids was not maintained beyond the first transfer. About 20% of larvae injected with hemolymph from aphids reared on infected Physalis transmitted PLRV (first passage). No further passage occurred, regardless of whether aphids were kept on immune or susceptible test plants. The evidence suggests that these isolates of PLRV were circulative, but not propagative, in two clones of M. persicae.