Intimate Rendezvous in a Tritrophic Context? Nothing but the Girls for Male Lysiphlebus testaceipes
نویسندگان
چکیده
In insects, mating often occurs after natal dispersal, and hence relies on a coevolved combination of sexual communication and movement allowing mate encounter. Volatile sex pheromones are widespread, generally emitted by females and triggering in-flight orientation of conspecific males. In parasitoid wasps, unmated females can start laying unfertilized eggs via parthenogenesis so that host patches could serve as sites of rendezvous for mating. Males could therefore use cues associated with host patches to focus their search on females that have successfully found oviposition sites. We hypothesized that in parasitoids exploiting herbivorous hosts, sex pheromones, and herbivore-induced plant volatiles (HIPV) should act in synergy, triggering male orientation toward ovipositing females. We tested this hypothesis with the aphid parasitoid Lysiphlebus testaceipes. Results from both field and laboratory experiments show that males are strongly attracted to virgin females, but that volatiles from aphid-infested plants have no effect on male orientation, neither has a cue, nor in interaction with the female sex pheromone. The absence of synergy between sex pheromones and HIPV contrasts with results on other species and raises interesting questions on mating systems and sexual selection in parasitoid wasps.
منابع مشابه
Tritrophic interaction of parasitoid Lysiphlebus testaceipes (Hymenoptera: Aphidiidae), greenbug, Schizaphis graminum (Homoptera: Aphididae), and greenbug-resistant sorghum hybrids.
Interactions of the parasitoid Lysiphlebus testaceipes (Cresson) and the greenbug, Schizaphis graminum (Rondani), on greenbug-resistant 'Cargill 607E' (antibiosis), 'Cargill 797' (primarily tolerance), and -susceptible 'Golden Harvest 510B' sorghum, Sorghum bicolor (L.) Moench, were tested using three levels of biotype I greenbug infestation. The parasitoid infestation rate was 0.5 female and 1...
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