COLOCALIZATION AND DIFFERENTIAL EXPRESSION OF PBAN-LIKE AND FMRFAMIDE-LIKE IMMUNOREACTIVITY IN THE SUBESOPHAGEAL GANGLION OF HELICOVERPA-ZEA (LEPIDOPTERA, NOCTUIDAE) DURING DEVELOPMENT

Pheromone biosynthesis activating neuropeptide (PBAN) stimulates sex pheromone production in several species of moths. We have used an antiserum to PBAN to map the distribution of PBAN-like immunoreactivity (PLI) in the subesophageal ganglion (SEG) of the larval and pupal stages of the corn earworm, Helicoverpa zea, and compared this distribution with that of the adult. The distribution of PLI within the SEG of larvae and pupae was quite similar to that found in adults, suggesting a function for PBAN other than the stimulation of pheromone biosynthesis. In all developmental stages studied, three groups of nerve cells in the SEG, and their projections, contained PLI. In adults and larvae, most of the cells containing PLI also had FMRFamide-like immunoreactivity (FLI). In pupae, however, a number of cells which appeared to have PLI and FLI in both larvae and adults, did not contain any detectable FLI, while the PLI appeared unchanged. The FLI returns to these cells during adult development. These immunocytochemical observations were corroborated by quantifying PLI and FLI by competitive ELISA; the level of extractable FLI in pupae was about 25% of that found in larvae, while PLI levels were unchanged.