The Ceratitis capitata is a very important agricultural pest, whose reproduction behaviour is controled by chemical signals. Males initiate mating by creating leks, where they release sexual pheromones to attract females. The main goal of this diploma thesis was to determine the influence of host plants on the composition of male sex-pheromones C. capitata and to compare emanations of wild males with those originating from laboratory population. We studied the chemical composition of volatiles, released by calling males C. capitata from laboratory and two wild populations, using two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC×GC-TOFMS), gas chromatography with electroantennographic and flame ionization detection (GC-EAD-FID). All data were statistically analyzed by multivariate data analyses. Significant differences were observed in the quantitative and qualitative composition of the chemical emanations among males from the three populations. The GC-EAD-FID analyses revealed fourteen antenally active compounds with a possible behavioral function. Isomenthone, geraniol, bornyl acetate, geranyl acetone and ethyl octanoate were newly identified antenally active compounds of C. capitata male sex pheromone. Statistical analyses indicated that males and females of...