Pheromone Analyses of the Anastrepha fraterculus (Diptera: Tephritidae) Cryptic Species Complex

The South American fruit fly Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) cryptic species complex is presently one of the most studied pest models in terms of speciation and population mating compatibility. The improvement of pest-control techniques has strongly relied on successful implementation of laboratory strains into wild populations. Pheromone communication plays an important role in the mating process in the South American fruit fly. Therefore, the main goal of the present study was to investigate the pheromone composition of 7 different populations, originating from geographically distant locations in Brazil and Argentina. Fourteen volatile compounds were identified in calling male emanations by GC×GC/TOF-MS and the data obtained were subsequently analyzed by multivariate statistics. The pheromone composition varied both quantitatively and qualitatively among the studied populations. These results will serve as the basis for further electrophysiological analyse

Identification of a new lepidopteran sex pheromone in picogram quantities using an antennal biodetector: (8E,10Z)-tetradeca-8,10-dienal from Cameraria ohridella

A major sex attractant released by the virgin female of the horse-chestnut leafminer Cameraria ohridella Deschka et Dimic (Lepidoptera: Gracillariidae) which devastates horse-chestnut trees in Europe, was identified in picogram quantities as (8E,10Z)-tetradeca-8,10-dienal without using spectral methods. The identification solely relied on gas chromatography with electroantennographic detection (GC-EAD), calculation of Kovats' indices of the active principle on different GC phases, and construction of antennal response spectra (EAG response profiles) to C-12 and C-14 saturated and unsaturated standards with different functional groups. The dienal was prepared by a stereospecific synthesis and shown to be highly active for conspecific males in pg amounts and Fully comparable to the natural substance. (C) 1999 Elsevier Science Ltd. All rights reserved

New mimics of the acetate function in pheromone-based attraction

Several analogues of (Z)-8-dodecenyl acetate (la), the major pheromone component of the Oriental fruit moth, Cydia molesta, with chloroformate and lactone functional groups in place of the acetate moiety, were synthesized and investigated for their biological activity at four evaluation levels, i.e. by electroantennography (EAG), electrosensillography (ESG), short-range sexual stimulation and activation in the flight-tunnel. We found very strict requirements on the shape as well as on the electron distribution of the acetate group for a productive interaction with the receptor. The behavioral results showed that, among the analogues investigated, the chloroformate lb, alken-4-olide 2a and also dodecyl acetate (lc) possess significant (60-85%) inhibitory activities. Based on electrophysiological evidence demonstrating that (i) only lb is competing with the major pheromone component la for the same receptor sites on the male antennal sensilla, (ii) lc elicits moderate EAG but no ESG responses and (iii) 2a does not produce any electrophysiologicai response at all, three possible inhibitory mechanisms by which these analogues are acting could be distinguished