Institut de Recherche sur la Biologie de l'Insecte, UPRESA-CNRS 6035, Faculté des Sciences, Parc Grandmont, 37200 Tours, France.
Platyparea poeciloptera is a serious pest for young asparagus stems in Europe. Olfactometric and EAG techniques were used to know if volatiles emitted by the spears were perceived by the two sexes of the fly, and to study if the flies use an anemotactic mechanism in their host finding. Two- and four-day-old males were attracted by asparagus, while in females, the results were not so clear. Only two-day-old females seemed to present a chemoanemotaxis. They seemed to be better attracted by the simultaneous presence of males and host plants. Volatiles were analysed in head-space of asparagus spears by GC/MS, using Solid Phase microextraction (SPME). Six common volatiles were identified which will be tested by EAG on next generation. Observed trisulfides and tetrasulfides could be considered as degradation compounds of asparagusic acid, a cyclic thiosulfinate. Preliminary experiments show that visual cues can also be used by the adult flies.