| Abstract: | The female sex pheromone of the processionary moth Thaumetopoea pityocampa has been reinvestigated to look for possible minor components. Examination by GC-MS and GC-EAD of the contents of virgin female glands, after stimulation with PBAN (pheromone-biosynthesis-activating neuropeptide), showed that the major component, (Z)-13-hexadecen-11-ynyl acetate (1), appears to be the only pheromone compound present in the gland. Comparison of female attractivity with that of the natural extract and synthetic (Z)-13-hexadecen-11-ynyl acetate showed that this chemical is able to elicit a similar activity to that displayed by virgin females in a wind tunnel. In single cell recording experiments, two specialist receptor cell types were found in the trichoid sensilla. One cell 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 components of the pheromone blend of other Thaumetopoea spp., and constitutes a further example of interspecific inhibitor receptor cells. Our results show that the processionary moth may not need minor components for successful mate recognition. |
