Identification and field optimisation of the female sex pheromone of the rice leaffolder, Cnaphalocrocis medinalis in India

Abstract

AbstractAnalysis of ovipositor washings from virgin female Cnaphalocrocis medinalis Guenée (Lepidoptera: Pyralidae) of Indian origin by linked gas chromatography 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 as (Z)‐11‐hexadecenyl acetate, (Z)‐13‐octadecenyl acetate and (Z)‐13‐octadecen‐1‐ol with (Z)‐13‐octadecenyl acetate present in amounts of between 0.25 and 1.5 ng per ovipositor and the other two components at less than 10% of this. Trace quantities of octadecyl acetate were identified by mass spectrometry but no electroantennographic responses were observed to this compound. Field trials conducted with a range of blends of the three electrophysiologically‐active compounds showed that blends containing between 5% and 30% (Z)‐11‐hexadecenyl acetate in (Z)‐13‐octadecenyl acetate dispensed from either white rubber septa or polythene vials were more attractive to male moths than a virgin female moth. Addition of (Z)‐13‐octadecen‐1‐ol reduced attractiveness to male moths in the blends and concentrations tested.