Estudo do feromônio sexual de diferentes populações do complexo Anastrepha fraterculus (Wiedemann, 1830) (Diptera:Tephritidae)

Abstract

The Anastrepha fraterculus cryptic species complex is nowadays one of the most studied model of agricultural pest in terms of speciation and population compatibility. The improvement of the control techniques of this pest is necessary for the successful implementation of the sterile laboratory populations into the wild populations. The pheromone communication plays an important role in the mating behavioral of this species. The males aggregate in leks and emit volatiles, which attract females for mating, however the exact composition of the male pheromone blend was not elucidated yet. Therefore, the main goal of this study was (i) to investigate the male pheromone composition from seven populations of A. fraterculus complex from geographically distinct regions within Brazil and Argentina, (ii) to elucidate the chemical composition of the volatiles emitted by males from laboratory population originated from state Alagoas and to identify the compounds which mediate the behavioral response in conspecific females. The two-dimensional gas chromatography coupled to mass spectrometric time-offlight detector (GC×GC/TOFMS) and consequently the multivariance analyses revealed quantitative and qualitative differences in the male born volatiles of the seven studied populations. Gas chromatography coupled to electoantenographic detector (GC-EAD) together with GC×GC/TOFMS analyses resulted in identification of 29 compounds in the aeration extracts of males from Alagoas population. The GC-EAD experiments with conspecific females from this population demonstrated that only six compounds, namely α-pinene, limonene, (Z)-3-nonen-1-ol, (E,Z)-3,6-nonadien-1-ol, (E,E)-α-farnesene and (S,S)-(-)-epianastrephin elicited depolarization in female antenna of this species. A synthetic mixture composed of EAD-active compounds elicited behavioral response in females similarly to headspace samples of conspecific males, whereas these two treatments elicited higher responses than a hexane control. This indicates that these six compounds act as sex pheromone for A. fraterculus females and therefore are considered as a promising tool for an effective control of this pest.