Attractiveness of different colours to Scaphoideus titanus Ball(Hemiptera: Cicadellidae) adults
Abstract: Laboratory and field tests were performed to ascertain a possible role of visual cuesfor Scaphoideus titanus during the location of a host plant. In laboratory, two choice colour testswere 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 threecoloured (yellow, red, blue) sticky traps were positioned in an organic vineyard and replacedonce a week, for two summers (2008 and 2009). In both seasons the yellow traps capturedsignificantly more individuals (either males or females) and had the highest sex rate (percentageof males on the total captures) followed by red and blue. Our investigation suggests that, despitea partial different response between laboratory and field tests, S. titanus adults are influenced byvisual cues present in their habitat. The possible reasons of the different responses observed inlab and field are discussed.