Abstract

Barley yellow striate mosaic virus (BYSMV, genus Cytorabdovirus, family Rhabdoviridae) is persistently transmitted by the planthopper Laodelphax striatella (Fallen) and reached to 58 and 79% in cereal disease summer nurseries in Syria (Sargaya station) and Lebanon (Terbol station) during 2002, respectively. Three different species of planthoppers were collected from ICARDA stations in Syria (Tel-Hadya, Aleppo) and Lebanon (Terbol station, Beqa\\\\\\\'a Valley) and evaluated for their efficiency in transmitting BYSMV. Results showed that only L. striatella (Hemiptera: Delphacidae) transmitted BYSMV efficiently. BYSMV transmission levels were obtained, 52 and 90% in barley, 96 and 90% in wheat and 67 and 87% in oat, when using 6 and 48 hours for virus acquisition, respectively. Sixteen larvae and 20 adults of L. striatella fed on BYSMV-infected plants for 48 h, then each was transferred to a single wheat plant at daily intervals for 30 consecutive days. All plants were tested three weeks after inoculation for the presence of the virus by the tissue-blot immunoassay (TBIA). Results obtained indicated that 31% of the larvae and 25% of the adults transmitted the virus. The latent period of BYSMV in L. striatella varied from 6 to 17 days. There was a great variation in the infectious (viruliferous) period of individual planthoppers, which varied between 3-24 days for larvae and 1-8 days for adults. Many individual insects (either larvae or adults) showed intermittent BYSMV transmission