Impact of the vibroscape on spittlebug-plant interaction

Insects are continuously exposed to a vibroscape, namely the array of substrate-borne vibrations produced by conspecifics, heterospecifics, or abiotic sources, which influences their interaction with their surroundings. However, the extent to which the vibroscape influences pest-plant interactions remains poorly understood. Here we tested the impact of intra- and inter-specific vibrational stimuli on host plant selection, post-alighting, probing, and feeding behaviors by the meadow spittlebug Philaenus spumarius, that is, the main European vector of the xylem-limited bacterium Xylella fastidiosa. Vibrational signals reduced spittlebug presence on the apical portion of plants, typically preferred in controls, with no differences between abiotic and antagonist-associated vibrations, indicating a generic and non-specific effect. In contrast, only the vibrations associated with spider and ant triggered freezing upon alighting. Ant vibrations reduced the number of insects engaging in probing activities by 23%, and the number of probing spittlebugs reaching xylem vessels and initiating xylem sap ingestion by 52%. Additionally, spittlebugs feeding on plants treated with ant vibrations exhibited delayed access to xylem vessels and significantly shorter ingestion duration. Besides antagonist-associated vibration, the male hierarchy call caused the highest rate of abandonment of the treated plants (48%) and led to longer non-probing periods, extended xylem testing, and delayed the onset of sustained ingestion, while the female rejection signal increased jumping frequency and prolonged non-probing and xylem testing/tasting not followed by sap ingestion. Eventually, our findings pave the way for the integration of semiophysicals in strategies aimed at interfering with spittlebug-plant interaction and potentially mitigating the spread of X. fastidiosa.