PBAN REGULATION OF PHEROMONE BIOSYNTHESIS IN FEMALE TOBACCO HORNWORM MOTHS, MANDUCA-SEXTA (L)

Manduca sexta females that were decapitated produced no pheromone during the scotophase following decapitation, indicating that they were free of pheromone biosynthesis activating neuropeptide (PBAN). When deuterated hexadecanoic or (Z)-11-hexadecenoic acid was applied to the sex pheromone glands of decapitated or intact females of the same age, and allowed to incubate in vivo for 24 h, deuterium labeled Delta-11- and Delta-10,12-unsaturated 16-carbon fatty acids were produced in both types of females. Injection of PBAN into intact or decapitated females 23 h after application oi labeled acids had no effect on the production of unsaturated labeled fatty acids. However, deuterium labeled aldehydes were produced only in females that were injected with PBAN. Therefore, in this species, PBAN activates the process by which fatty acyl precursors in the pheromone gland are converted into the pheromonal aldehydes. (C) 1995 Wiley-Liss, Inc.