PHEROMONOTROPIC ACTIVITY IN THE GYPSY-MOTH LYMANTRIA-DISPAR - EVIDENCE FOR A NEUROPEPTIDE

The brain-suboesophageal ganglion complex of the gypsy moth, Lymantria dispar, contains pheromonotropic activity detectable using a Helicoverpa zea in vivo bioassay for pheromone-biosynthesis-activating neuropeptide. Pheromonotropic activity was detected as early as the third larval instar and was present throughout development and through day 6 post-eclosion. Activity in the adult is presumably associated with pheromone production, while it is speculated that larval activity may be related to melanization. Adult pheromonotropic activity is associated with a peptide of approximately 3.500 kDa. It is heat labile and only partially stable when incubated at 35-degrees-C or exposed to freeze-thawing. Isolation of L. dispar pheromonotropic factor should facilitate the elucidation of the mechanism of pheromone production in this insect pest.