Reidentification of Sex Pheromones of Tea Geometrid Ectropis obliqua Prout (Lepidoptera: Geometridae).

Abstract

Tea geometrid Ectropis obliqua Prout (Lepidoptera: Geometridae) is an important defoliator of the tree crop Camellia sinensis L. in China. The sex pheromones of E. obliqua have not been identified, but have potential importance relative to the biological control of this predator. In this study, the female sex pheromones of E. obliqua were identified and evaluated for use in the monitoring and mass trapping of this pest. The sex pheromone extracts were subjected to gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry. The identified chemicals were synthesized and applied to wind-tunnel tests and field experiments. (Z,Z,Z)-3,6,9-octadecatriene and 6,7-epoxy-(Z,Z)-3,9-octadecadiene were determined to be the primary sex pheromones produced by the female E. obliqua; the latter elicits the strongest electroantennogram responses from male E. obliqua antennae. However, males did not respond to single components in the wind-tunnel tests. The results of a field-trapping experiment indicated that a 4:6 v/v blend of (Z,Z,Z)-3,6,9-octadecatriene and 6,7-epoxy-(Z,Z)-3,9-octadecadiene was highly effective in attracting male moths.