Termination of sex pheromone production in mated females of the silkworm moth

✍ Scribed by Tetsu Ando; Kie Kasuga; Yohko Yajima; Hiroshi Kataoka; Akinori Suzuki

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 655 KB
• Volume: 31
• Category: Article
• ISSN: 0739-4462
• DOI: 10.1002/(sici)1520-6327(1996)31:2<207::aid-arch8>3.0.co;2-w

✦ Synopsis

A mating duration of more than 6 h was necessary to permanently terminate the production of the sex pheromone (bombykol) in the silkworm moth, Bornbyx mori L. (Lepidoptera: Bombycidae), although the female formed a bursa copulatrix including a spermatophore and laid fertilized eggs even after mating for only 0.5 h. The 6-h mated female again produced bombykol if given an injection ot synthetic pheromonotropic neuropeptide (PBAN), which is known to activate pheromone biosynthesis in a virgin female. Extracts of brainsuboesophageal ganglion (SG) complexes, which were removed from 6-and 24-h mated females, showed strong pheromonotropic activities. These results indicated that the pheromone gland of the mated female maintained its ability to biosynthesize bombykol; however, it could not produce pheromone due to a suppression of PBAN secretion from the SG. Furthermore, bombykol titers did not decrease after mating in females with a transected ventral nerve cord, even after the injection of a spermatophore extract, suggesting that the suppression of PBAN secretion was mediated by a neural signal and not by a substance in the spermatophore. The mated females accumulated (1 OE, 1 2 a -10,12-hexadecadienoic acid, a precursor of bombykol biosynthesis, in their pheromone glands as did decapitated females. o 1996 WiIey-Liss, Inc.