SEX-PHEROMONE OF FEMALE AFRICAN WHITE RICE STEM BORER, MALIARPHA-SEPARATELLA (LEPIDOPTERA, PYRALIDAE) FROM SIERRA-LEONE - IDENTIFICATION AND FIELD TESTING

Analysis of ovipositor washings of female Maliarpha separatella from Sierra Leone by high-resolution gas chromatography (GC) linked to a male electroantennograph (EAG) indicated the presence of three electrophysiologically active compounds. The GC retention times of these compounds were consistent with those of (Z)-9-tetradecen-1-ol, (Z,E)-9,12-tetradecadien-1-ol, and (E,E)-10,12-tetradecadien-1-ol. Analysis by EI and CI mass spectrometry of ovipositor washings confirmed these identifications and also indicated the presence of the saturated analog, tetradecan-1-ol. There was no evidence, from these analyses, of the corresponding aldehydes or acetates. The EAG-active compounds were present in the ovipositor washings in a ratio of approximately 2:3.5:1, with the major component constituting approximately 0.4 ng per ovipositor. GC-MS analysis of entrained female effluvia confirmed that the EAG-active compounds were released by virgin females. Field testing of the EAG-active compounds indicated that (Z,E)-9,12-tetradecadien-1-ol and (E,E)-10,12-tetradecadien-1-ol were attractive to male moths in ratios of between 9:1 and 39:1, while (Z)-9-tetradecen-1-ol was found to reduce trap catch when added to blends of the other two compounds.