Title: | The significance of background odour for an egg parasitoid to detect plants with host eggs |
Address: | "Institute of Biology, Freie Universitat Berlin, Haderslebener Strasse 9, D-12163 Berlin, Germany" |
ISSN/ISBN: | 0379-864X (Print) 0379-864X (Linking) |
Abstract: | "Scots pine has been shown to produce a volatile bouquet that attracts egg parasitoids in response to oviposition of the herbivorous sawfly Diprion pini. Previous analyses of headspace volatiles of oviposition-induced pine twigs revealed only quantitative changes; in particular, the sesquiterpene (E)-beta-farnesene was emitted in significantly higher quantities by oviposition-induced pine. Here we investigated whether (E)-beta-farnesene attracted the egg parasitoid Chrysonotomyia ruforum. We tested the behavioural response of C. ruforum females to different concentrations of (E)-beta-farnesene. Egg parasitoids did not respond to this sesquiterpene at either concentration tested. However, they did respond significantly to (E)-beta-farnesene when this compound was offered in combination with the volatile blend emitted from pine twigs without eggs. This response was dependent on the applied concentration of (E)-beta-farnesene. Further bioassays with other components [(E)-beta-caryophyllene, delta-cadinene] of the odour blend of pine were conducted in combination with the volatile blend from egg-free pine as background odour. None of the compounds tested against the background of odour from an egg-free pine twig were attractive to the egg parasitoid. These results suggest that the egg parasitoids responded specifically to (E)-beta-farnesene, but only when this compound was experienced in the 'right' context, i.e. when contrasted with a background odour of non-oviposition-induced pine volatiles" |
Keywords: | Animals Female Host-Parasite Interactions/physiology Hymenoptera/*physiology Odorants Oviposition Ovum/*physiology Pinus sylvestris/metabolism/parasitology/*physiology Sesquiterpenes/*metabolism Volatilization; |
Notes: | "MedlineMumm, Roland Hilker, Monika eng Research Support, Non-U.S. Gov't England 2005/03/25 Chem Senses. 2005 May; 30(4):337-43. doi: 10.1093/chemse/bji028. Epub 2005 Mar 23" |