"Parasitic weeds from the genus Orobanche considerably damage crop plants due to withdrawal of water, minerals and carbohydrates. The growth of the hosts is retarded and yield losses range from 5 to 100%. The proposed project is dealing with tritrophic aspects of the host-plant selection by the oligophagous fly Phytomyza orobanchia, a natural enemy of Orobanche species. The novel aspect and the main objective of the project is isolation and identification of Orobanche volatiles and Orobanche-induced host plant volatiles that attract P. orobanchia to its host, Orobanche spp. In order to address this problem, we will collect headspace volatiles of vegetative as well as flowering Orobanche spp. alone, of its hosts and of the combination of host and Orobanche. The headspace samples will be analysed using GC-MS and used for the identification of insect-behaviour-effecting compounds using GC-EAG analyses and flight tunnel experiments. The effectiveness of selected volatiles will be tested in field experiments. The results of this work are expected to improve the efficacy of biological control of Orobanche spp. e.g. through positive effects of selected kairomones on the efficacy of P. orobanchia; increased attraction to its host, mass trapping and redistribution and attraction of flies to use them as vectors of disease into the Orobanche population. The host institution will be Wageningen University (Wageningen, The Netherlands). The total duration of the proposed project will be 24 months through 2008-2010. The project will help, through the fellow, to join multidisciplinary knowledge in the research field. The training and new skills obtained will make the applicant more competitive, will enable him to extent his knowledge and will give the researcher the boost he needs to reach professional independence."