IDENTIFICATION AND FIELD OPTIMIZATION OF THE FEMALE SEX-PHEROMONE OF THE RICE LEAFFOLDER, CNAPHALOCROCIS-MEDINALIS IN INDIA

Analysis of ovipositor washings from virgin female Cnaphalocrocis medi nalis Guenee (Lepidoptera: Pyralidae) of Indian origin by linked gas c hromatography and electroantennography indicated the presence of three electrophysiologically-active compounds. These were identified on the basis of their gas chromatographic retention times and mass spectra a s (Z)-11-hexadecenyl acetate, (Z)-13-octadecenyl acetate and (Z)-13-oc tadecen-1-ol with (Z)-13-octadecenyl acetate present in amounts of bet ween 0.25 and 1.5 ng per ovipositor and the other two components at le ss than 10% of this. Trace quantities of octadecyl acetate were identi fied by mass spectrometry but no electroantennographic responses were observed to this compound. Field trials conducted with a range of blen ds of the three electrophysiologically-active compounds showed that bl end containing between 5% and 30% (Z)-11-hexadecenyl acetate in (Z)-13 -octadecenyl acetate dispensed from either white rubber septa or polyt hene vials were more attractive to male moths than a virgin female mot h. Addition of (Z)-13-octadecen-1-ol reduced attractiveness to male mo ths in the blends and concentrations tested.