LEAF VIBRATIONS AND AIR MOVEMENTS IN A LEAFMINER-PARASITOID SYSTEM

This paper analyzes the vibratory environment of the leafminer Phyllon orycter malella (Ger.) (Lep. Gracillariidae) and its parasitoid Sympie sis sericeicornis Nees (Hym. Eulophidae). Previous studies established that both the host and the parasitoid not only produce but also use l eaf vibrations: the former in order to escape ovipositor stings, the l atter as a physical cue in the foraging process. First we characterize vibration patterns produced by simulated mind and rain and discuss th e influence of these background vibrations on the host-parasitoid inte raction. Second, we present a method of producing leaf vibration patte rns of high repeatability. This technique allows us to characterize th e influence of the leaf as modifier of vibratory signals. We discuss h ow S. sericeicornis could use such spatially variable vibratory inform ation for between-mine foraging. Finally, a combined laser Doppler vib rometry-laser Doppler anemometry study revealed that leaf vibrations i nduce air movements in their immediate surroundings with characteristi c temporal and spatial structures. We discuss if and how host-related information contained in the air particle displacement can be used by parasitoids. (C) 1998 Academic Press.