Attractiveness of different colored sticky traps for spittlebug vectors of Xylella fastidiosa

Philaenus spumarius is the main vectors of Xylella fastidiosa in Europe. For integrated pest management, the monitoring of the pest is crucial to planning an efficient and sustainable control strategy. The monitoring of spittlebug adults is carried out mainly using the sweeping net. Nevertheless, several studies have reported its ineffectiveness in sampling insects from the olive canopy. Moreover, using the sweeping net requires quite a lot of time and a skilled operator.
So far, only one study has been carried out on the attractiveness of different color sticky traps for adults of P. spumarius. The results showed that the most attractive one was yellow. Nevertheless, the use of yellow sticky traps in a field has highlighted a low efficacy in monitoring spittlebugs. In order to improve the knowledge on this topic a new studies on the attractiveness of different colors are needed. Within the Life Resilience project, a field trial, aimed at testing different color sticky traps, has been carried out in three different olive groves in Tuscany in the 2020 fall. The tested colors were white, red, blue, brown, dark green, yellow (as positive control) and transparent as negative control. For each color, two 20x25 cm double-sided sticky boards were positioned in the olive grove respectively at 50 and 100 cm from the ground. Traps were controlled every fifteen days and trapped specimens of P. spumarius and N. campestris were removed, identified, sexed and counted. Moreover, during every on-site visit a monitoring of the population density was carried out by means of the sweeping net. As previously recorded, yellow colored sticky traps showed the greatest attractiveness towards P. spumarius, especially males, while only a few N. campestris were caught by the traps overall. Further studies on the response to colors are planned in order to clarify these preliminary results.