PERCEPTION OF SPECIES-SPECIFIC VOLATILE S UBSTANCES IN THE DESERT LOCUST SCHISTOCERCA-GREGARIA (CAELIFERA, ACRIDIDAE)

The Desert Locust Schistocerca gregaria (Forskal 1775) emits several v olatile substances which may have a pheromonal character. Identified s ubstances of the headspace, like phenol, veratrol, guaiacol, 1,2,3-tri methoxybenzene, benzylcyanide and a blend of these compounds, were ele ctroantenno-graphically tested in sexually mature and immature males a nd females. The blend corresponded to the headspace of sexually mature , yellow coloured males. All compounds tested evoked a significant res ponse of the locust antenna depending on their concentration, ie there are receptors on the antennae which percept the chemicals tested. A s trong reaction to the blend of the volatile substances tested was obse rved in immature females and males; the response, however, could not b e attributed to a single compound. The additive or synergistic effects of the compounds have to be tested.