|Davis, N. - UNIV. AZ, TUCSON, AZ|
|Christensen, T. - UNIV. AZ, TUCSON, AZ|
|Hildebrand, J. - UNIV. AZ, TUCSON, AZ|
Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 1999
Publication Date: N/A
Interpretive Summary: Female moths use perfumes called pheromones to attract mates. Production of pheromones usually occurs only at specific times of the night. Knowing what factors regulate the production of pheromones and how these factors act is important to understanding the pheromone communication systems of these insects. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, USDA ARS and the Division of Neurobiology, University of Arizona, have been studying how the tobacco budworm moth (Heliothis virescens), a serious pest of cotton in the United States, regulates the production of pheromones. Their studies have shown that these pests use chemicals called neuropeptides, produced in the brain, to stimulate pheromone production. These neuropeptides are present also in a nerve center, or ganglion, that is in close association with the gland that produces the pheromones. The scientists also discovered that the neuropeptides function in conjunction with nervous signals and that both nerve signals and neuropeptides are required for the moths to produce pheromones. This research has provided important fundamental knowledge on how these pest moths regulate production of sex pheromones. The results also provide important information for development of new strategies for pest control based on the use of insect neuropeptides analogs to change the natural production of pheromone and thereby inhibit mating.
Technical Abstract: This work was undertaken in an effort to clarify the possible role of neural control of sex pheromone biosynthesis in the female of Heliothis virescens. Severance of the connection of the ventral nerve cord to the terminal abdominal ganglion (TAG), or severance of nerves extending from the TAG, resulted in a severe reduction in the production of sex pheromone that normally occurs during the scotophase. However, the amount of pheromone extracted from the glands of these surgically manipulated females was greater than that from glands of normal females extracted during the photophase when pheromone levels are low or not detectable. Injection of an extract of female TAGs into virgin females resulted in the production of sex pheromone. Chromatographic separation of extracts of the TAG and of the brain/subesophageal ganglion complex revealed that the TAG contains pheromonotropic peptides with retention characteristics very similar to those of the BR/SEG. Results from ELISAs indicated that the pheromonotropic peptides of the TAG have some degree of homology at the C-terminus to Hez-PBAN. However, the structures of the peptides from H. virescens are not identical to Hez-PBAN. Our results demonstrated that in H. virescens, neural control combined with hormonal regulation, is essential for optimal production of sex pheromones.