REINVESTIGATION OF FEMALE SEX-PHEROMONE OF PROCESSIONARY MOTH (THAUMETOPOEA-PITYOCAMPA) - NO EVIDENCE FOR MINOR COMPONENTS

The female sex pheromone of the processionary moth Thaumetopoea pityoc ampa has been reinvestigated to look for possible minor components. Ex amination by GC-MS and GC-EAD of the contents of virgin female glands, after stimulation with PBAN (pheromone-biosynthesis-activating neurop eptide), showed that the major component, (Z)-13-hexadecen-11-ynyl ace tate (1), appears to be the only pheromone compound present in the gla nd. Comparison of female attractivity with that of the natural extract and synthetic (Z)-13-hexadecen-11-ynyl acetate showed that this chemi cal is able to elicit a similar activity to that displayed by virgin f emales in a wind tunnel. In single cell recording experiments, two spe cialist receptor cell types were found in the trichoid sensilla. One c ell type was tuned to enyne acetate 1, The other one was tuned to (Z,Z )-11,13-hexadecadienal and (Z)-13-hexadecen-11-ynal, the major compone nts of the pheromone blend of other Thaumetopoea spp., and constitutes a further example of interspecific inhibitor receptor cells. Our resu lts show that the processionary moth may not need minor components for successful mate recognition.