Sex pheromone components of Casuarina moth, Lymantria xylina

cis-7,8-Epoxy-2-methyleicosane is a sex pheromone component of the Casuarin a moth, Lymantria xylina Swinhoe. The compound was extracted from pheromone glands of female moths and was identified by coupled gas chromatographic-e lectroantennographic detection (GC-EAD) and GC-mass spectrometry. In field experiments in Taiwan, traps baited with either or both of (7R,8S)-cis-7,8- epoxy-2-methyleicosane (>99% eel [termed here (+)-xylinalure] and (7S,8R)-c is-7,8-epoxy-2-methyleicosane (>99% eel [termed here (-)-xylinalure] captur ed male L. xylina. Addition of further candidate pheromone components to xy linalure did not enhance its attractiveness. Demonstration of whether or no t female L. xylina produce both optical isomers of xylinalure, and determin ation of the ratio, will require pheromone extract analyses on a chiral, en antiomer-separating column (as yet unavailable) or derivatization of epoxid es in accumulated gland extracts. Attraction of male L. xylina to either en antiomer of xylinalure contrasts with enantiospecific production of, and/or response to, epoxy pheromones in congeners. With no other nocturnal lymant riid moth known in Taiwan to utilize xylinalure for pheromonal communicatio n, enantiospecific "fine tuning" of xylinalure, or evolution of a more comp lex pheromone blend, may not have been necessary for L. xylina to maintain specificity of sexual communication. Racemic xylinalure will be appropriate for pheromone-based detection surveys of L, xylina in North America.