ISOLATION OF OVIPOSITION PHEROMONE FROM THE EGGS OF THE SANDFLY LUTZOMYIA-LONGIPALPIS

Semiochemical components of eggs of the sandfly Lutzomyia longipalpis (Diptera: Psychodidae) were separated by high performance liquid chrom atography. HPLC fractions were examined quantitatively and qualitative ly by gas chromatography (GC). A bioassay was used to determine the ov iposition attraction of gravid L. longipalpis to each of the fractions separately and a peak responsible for the semiochemical activity was identified. Gravid flies were placed in individual oviposition tubes t o determine if the peak of interest was an oviposition stimulant. The active semiochemical fraction attracted gravid flies for oviposition. Furthermore, egg laying was enhanced: gravid flies exposed to the pher omone oviposited earlier and laid more eggs than control flies. GC ana lysis indicated that 1200 eggs (2 days old) gave a yield of 12.75 mug of active pheromone. This fraction had similar HPLC and GC retention t imes to caryophyllene oxide, suggesting comparable polarity and molecu lar weight.