Dispersal patterns and chromatic response of Scaphoideus titanus Ball (Homoptera Cicadellidae), vector of the phytoplasma agent of grapevine flavescence dorée

Abstract

Abstract 1 Scaphoideus titanus Ball, a nearctic leafhopper introduced into Europe in the 1950s, is known to be the vector of the phytoplasma agent of flavescence dorée (FD), a persistent disease of grapevine. Knowledge of its dispersal patterns is thus very important to prevent disease outbreaks.2 Yellow sticky traps were used to study the seasonal flight activity of S. titanus, its vertical flight, its movement outside the vineyard and the influence of plant density. Sticky traps of different colours (yellow, red, blue, and white) were also compared. The behaviour of males and females was tested for all those conditions.3 Abundance was greater in normal than in low plant density conditions, and a positive relationship was found between number of plants per square metre and presence of S. titanus. Leafhoppers did not appear capable of spreading significantly outside a vineyard. Few individuals were trapped above the canopy. Red sticky traps caught more individuals than white, yellow or blue, with the latter showing a poor attractiveness. Sex ratio was almost always male biased.4 Scaphoideus titanus is monophagous and appears incapable of great dispersal away from its host plant, and females are less likely to fly than males. Further studies on the influence of different factors on the behaviour of this leafhopper are suggested.