Antennal ampullary glands of Helicoverpa zea (Lepidoptera: Noctuidae)

In adult moths, the cephalic aorta terminates in an apical sack from which extends a pair of optic and antennal vessels that lie on either side of the esophagus, at the dorsoanterior surface of the brain. The base of each antennal vessel is dilated to form an ampulla that contains an oval mass of tissue, the antennal ampullary gland (AAG). An ultrastructural study revealed that the AAG of the corn earworm moth, Helicoverpa zea (Lepidoptera, Noctuidae), is composed of a single type of 40-50 parenchymal cells that produce secretory granules. The secretory material is released into the lymph channel of the ampullary vessel, suggesting that the AAG is an endocrine gland. Unlike the prothoracic gland and the corpus allatum, the AAG does not receive direct neural innervation; however, portions of the aortal muscle, associated with the ampullary wall, contain neurosecretory terminals and some of their products may also affect the AAG. No morphological differences were found between the AAG of males and females, with the exception that the glands in males were slightly larger. The function of the AAG remains unknown at this time. Because the AAG is located within the ampulla of the antennal vessel, one could assume that the product(s) of this gland may influence the response of the antennal sensory neurons to external stimuli.