ASSOCIATION BETWEEN LASCIONYCTA WYATTI (NOCTUIDAE)AND THE TOXIC PLANT AMBROSIA CHAMISSONIS (ASTERACEAE)
Joanna Dojillo-Mooney, Jonathan E. Page, Murray B. Isman1,and G.H. Neil Towers
Departments of Botany and 1Plant Science, University ofBritish Columbia, Vancouver, Canada V6T 1Z4,
A group of sulfur-containing polyynes (thiarubrines) exhibit significantlight-mediated antibiotic activity particularly towards fungi. Thesephytochemicals have been isolated from several members of the Asteraceaeincluding Ambrosia chamissonis a species found along sandy beachesin British Columbia. The larvae of a rare noctuid moth, Lascionyctawyatti, were found to be associated with the stems and roots of thisplant. High performance liquid chromatographic (HPLC) analyses ofL. wyatti larvae found significant amounts of several thiarubrines. Artificial diets containing thiarubrines were shown to be tolerated bythese larvae. The same diets, however, were toxic to Manduca sexta larvaeand growth inhibitory to larvae of Spodoptera litura.