|Lopez, Juan De Dios|
|Teran Vargas, Antonio|
Submitted to: Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2008
Publication Date: 8/1/2009
Citation: Groot, A.T., Inglis, O., Bowdridge, S., Santangelo, R., Blanco, C.A., Lopez, J., Teran Vargas, A., Gould, F., Schal, C. 2009. Geographic and Temporal Variation in Moth Chemical Communication. Evolution. 63(8):1987-2003. Interpretive Summary: Our knowledge of the sexual biology of noctuids is still incomplete. In order to implement technically and environmentally sound pest control measurements, we need to study different aspects of the reproductive biology of pests. The genus Heliothis/Helicoverpa is considered a ‘billion dollar pest’ due to the great destructive crop potential of these important pests such as the bollworm, the American bollworm (H. armigera), tobacco budworm and Heliothis subflexa. There are areas where these pests coincide in space and time and in order to make an effective use of, let say, pheromones and/or sterile insect releases, we need to know the chemical communication among species and strains. On this paper, it is demonstrated that a single species has developed a unique blend of chemistry in order to attract its own species and not to be interfered by those that produce similar blends of compounds. These findings have implications in our understanding on why certain strains are not attracted to pheromone traps, leaving advisors, extension personnel and growers without the proper use of an effective predictive tool.
Technical Abstract: Unlike acoustic and visual communication, chemical communication cues have not been viewed in the background of a chemically noisy habitat. Species with similar chemical cues may not only directly interfere with each other's communication channels, but the presence and abundance of other species may indirectly affect the signal-to-noise ratio in the habitat. If variation in sexual communication is due to variation in the habitat, these communication cues are subject to habitat-dependent selection. Such selection may be expected when variation is found not only between geographic regions, but also within regions when environmental variables change from year to year. We quantified variation in the sex pheromone blends of two closely related noctuid moth species, Heliothis virescens and H. subflexa, in five different regions for three consecutive years. In addition, we assessed variation in male response in one region for 2-3 consecutive years. We found significant geographic and temporal variation in the ratios of sex pheromone blend components as well as in male response. In addition, local females attracted significantly more local males than females originating from another region. Positive assortative attraction can result in local selection on pheromone communication and may cause population divergence, a first step in speciation.