Scaphoideus titanus, a Possible Vector of Grapevine Yellows in New York. M. Maixner, Biologische Bundesanstalt für Land- und Forstwirtschaft, Institut für Pflanzenschutz im Weinbau, 5550 Bernkastel-Kues, Germany. R. C. Pearson, E. Boudon-Padieu, and A. Caudwell. Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456; and Station de recherche sur les mycoplasmes et les arbovirus des plantes, I.N.R.A., 21034 Dijon, France. Plant Dis. 77:408-413. Accepted for publication 20 November 1992. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/PD-77-0408.

Scaphoideus titanus, the natural vector of grapevine flavescence dorée (FD), is widespread in New York. It was found closely associated with both wild Vitis riparia and cultivated V. vinifera, but it prefers V. riparia. Adult leafhoppers migrate from surrounding wild grapevines into the peripheral parts of vineyards. V. vinifera vines with symptoms of grapevine yellows (GY) disease were concentrated along the borders of vineyards. Even near GY-affected vineyards, V. riparia vines never exhibited symptoms of this disease. Symptoms of an MLO infection developed in 29% of Vicia faba plants fed on by field-collected S. titanus. However, potted V. vinifera‘Chardonnay’ on which the same leafhoppers were fed did not develop symptoms of GY within 1 yr. Thirteen percent of 371 S. titanus leafhoppers collected from V. vinifera or V. riparia reacted positively in enzyme-linked immunosorbent assays (ELISAs) with polyclonal antibodies to FD, and MLOs were detected by immunosorbent electron microscopy in extracts of ELISA-positive leafhoppers. The results support the hypothesis of a common North American origin of FD and its vector, S. titanus, but further research is necessary to confirm the relationship of S. titanus and the pathogens found in this leafhopper to GY.