Axonal composition of esophageal nerve in the corn earworm moth, Helicoverpa zea (boddie) (Lepidoptera : Noctuidae)

Using the cobalt back-filling technique, we investigated the axonal input to the esophageal nerve (EN) from the brain and subesophageal ganglion in the corn earworm moth, Helicoverpa zea (Lepidoptera : Noctuidae). Retrograde filling of the EN followed by silver intensification revealed axons originating from the protocerebral neurosecretory cells in groups M1 and M3, neurosecretory cells of the frontal ganglion and from maxillary and mandibular cells of the subesophageal ganglion. The EN may be acting as a potential release site for neurosecretion from these cells and should be considered as a constituent part of the retrocerebral complex in H. zea, and possibly in other species of moths.