Olfactory responses to volatile organic compounds and movement parameters of Philaenus spumarius and Cicadella viridis

Abstract

AbstractXylella fastidiosa, the causal agent of several diseases in crops of economic interest, could be rapidly transmitted and spread throughout the agroecosystem landscape by xylem sap‐feeding insects. Chemical signals in the environment drive the behaviour of insects. Attractive or repulsive responses to signals may affect insects’ fitness, survival and reproduction, and elicit different movement patterns. Specific movement patterns derived from olfactory cues towards the selection of plants for feeding may trigger the transmission of the pathogen by the insect. Thus, understanding vectors’ olfactory response and movement parameters are of utmost importance. This work aimed to assess the olfactory response of Philaenus spumarius and Cicadella viridis adults to two Volatile Organic Compounds (VOCs) (cis‐3‐hexenyl acetate and cis‐3‐hexen‐1‐ol) present in almond, olive and vine leaves. Insects’ behavioural responses were conducted in a four‐arm olfactometer, and the two aforementioned VOCs were tested at different concentrations (5, 10, 20 and 30 µg/µl). At the lowest concentration, females of P. spumarius were significantly attracted by the two VOCs. At the highest concentrations, no significant differences were detected among treatments. Cicadella viridis individuals showed no significant differences in their choice at any concentration. Additionally, the walking movement of these insects was also studied in the absence of food. Females of P. spumarius and C. viridis can walk significantly more at a significantly higher velocity than males. Knowledge of the olfactory response of X. fastidiosa vectors and their movement parameters can be essential to develop new tools to limit the spread of this phytopathogen.