CONTROL OF PHEROMONE BIOSYNTHESIS IN MATED REDBANDED LEAFROLLER MOTHS

Mating in the redbanded leafroller moth, Argyrotaenia velutinana, caus es a permanent decline in pheromone liters. Three hours following the termination of mating, phermone titers were significantly decreased fr om premating levels, and titers remained low for at least four days af ter mating. Pheromone titers were similar in females that had been dec apitated or mated for twenty-four hours. In the redbanded leafroller m oth, two peptides control pheromone production. The pheromone biosynth esis activating neuropeptide is produced in tbe brain and the pheromon otropic bursa peptide is produced in the corpus bursae. Both peptides stimulated pheromone biosynthesis in mated females and extracts prepar ed from brains and bursae of mated females contained pheromonotropic a ctivity. However, severing the ventral nerve cord before mating preven ted the decline in pheromone titer that occurred in mated females. Hem olymph collected during scotophase from mated females did not have phe romonotropic activity, whereas hemolymph collected during scotophase f rom virgin females contained activity. These results indicate that mat ing produces a signal sent by the ventral nerve cord to the brain to s top the release of pheromone biosynthesis activating neuropeptide. o 1 993 Wiley-Liss, Inc.