Attractiveness of different colours to Scaphoideus titanus Ball (Hemiptera: Cicadellidae) adults

Laboratory and field tests were performed to ascertain a possible role of visual cues for Scaphoideus titanus during the location of a host plant. In laboratory, two choice colour tests were made in a Y-tube to compare the attractiveness of blue (peak wavelength: 475nm), green (521nm), yellow (573nm) and red (650nm). The observed preference order was yellow > red > green > blue for males and red > yellow > green > blue for females. In field, nine groups of three coloured (yellow, red, blue) sticky traps were positioned in an organic vineyard and replaced once a week, for two summers (2008 and 2009). In both seasons the yellow traps captured significantly more individuals (either males or females) and had the highest sex rate (percentage of males on the total captures) followed by red and blue. Our investigation suggests that, despite a partial different response between laboratory and field tests, S. titanus adults are influenced by visual cues present in their habitat. The possible reasons of the different responses observed in lab and field are discussed.