Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 29, 1996
Publication Date: N/A
Interpretive Summary: Production of sex pheromone, which mediates mating in most species of moths, is controlled by a hormone produced in the head. Unlike other species of moths studied thus far, cutting of the abdominal nerve in the gypsy moth prevents pheromone production. We needed to visualize the distribution of this hormone in the nervous system and determine what role such distribution may have on pheromone production in this rather unusual case. We used an antibody raised against the above hormone in immunocytochemical techniques to determine the distribution of cells that may be producing this hormone. Immunoreactive cells and their processes were found in both cerebral and abdominal parts of the nervous system. The results are discussed in relation to the regulation of sex pheromone production in the gypsy moth. The information will be useful to scientists studying the control of pheromone production and reproductive physiology in this important pest insect.
The production of sex pheromone in many moths is regulated by the neuropeptide pheromone biosynthesis activating neuropeptide (PBAN). Production of pheromone in the gypsy moth, Lymantria dispar, is prevented in females with a transected ventral nerve cord (VNC). To begin to understand the cellular basis for this dependence on the VNC, we sought to determine the distribution of PBAN in the central nervous system and its neurohemal sites. Using an antiserum to L. dispar-PBAN in immunocytochemical methods, we have mapped the distribution of PBAN-like immunoreactivity (PLI). PLI is found in three clusters of ventral midline somata in the subesophageal ganglion (SEG), three clusters of midline cells in each segmental ganglion, and in the posterolateral abdominal ganglia, in paired bilateral clusters of cells. A swelling of the nervus corpus cardiaci ventralis (NCCV) forms an unusual neurohemal structure that receives axons from the two anterior clusters of cells in the SEG. In the abdominal ganglia, the posterolateral cluster of cells has immunoreactive axons exiting the ganglia via the ventral roots. Thus, while descending interneurons from the SEG may be regulatory in the production of sex pheromone, our findings raise the additional possibility that neurosecretory cells in the segmental ganglia, under descending regulation, could also be important in evoking production of sex pheromone.