Leaf Vibrations and Air Movements in a Leafminer–Parasitoid System

This paper analyzes the vibratory environment of the leafminerPhyllonorycter malella(Ger.) (Lep. Gracillariidae) and its parasitoidSympiesis sericeicornisNees (Hym. Eulophidae). Previous studies established that both the host and the parasitoid not only produce but also use leaf vibrations: the former in order to escape ovipositor stings, the latter as a physical cue in the foraging process. First we characterize vibration patterns produced by simulated wind and rain and discuss the influence of these background vibrations on the host–parasitoid interaction. Second, we present a method of producing leaf vibration patterns of high repeatability. This technique allows us to characterize the influence of the leaf as modifier of vibratory signals. We discuss howS. sericeicorniscould use such spatially variable vibratory information for between-mine foraging. Finally, a combined laser Doppler vibrometry–laser Doppler anemometry study revealed that leaf vibrations induce air movements in their immediate surroundings with characteristic temporal and spatial structures. We discuss if and how host-related information contained in the air particle displacement can be used by parasitoids.