title: Geographic variation in sexual attraction of Spodoptera frugiperda corn- and rice-strain males to pheromone lures.
abstract: The corn- and rice-strains of Spodoptera frugiperda exhibit several genetic and behavioral differences and appear to be undergoing ecological speciation in sympatry. Previous studies reported conflicting results when investigating male attraction to pheromone lures in different regions, but this could have been due to inter-strain and/or geographic differences. Therefore, we investigated whether corn- and rice-strain males differed in their response to different synthetic pheromone blends in different regions in North America, the Caribbean and South America. All trapped males were strain-typed by two strain-specific mitochondrial DNA markers. In the first experiment, we found a nearly similar response of corn- and rice-strain males to two different 4-component blends, resembling the corn- and rice-strain female blend we previously described from females in Florida. This response showed some geographic variation in fields in Canada, North Carolina, Florida, Puerto Rico, and South America (Peru, Argentina). In dose-response experiments with the critical secondary sex pheromone component (Z)-7-dodecenyl acetate (Z7-12:OAc), we found some strain-specific differences in male attraction. While the response to Z7-12:OAc varied geographically in the corn-strain, rice-strain males showed almost no variation. We also found that the minor compound (Z)-11-hexadecenyl acetate (Z11-16:OAc) did not increase attraction of both strains in Florida and of corn-strain males in Peru. In a fourth experiment, where we added the stereo-isomer of the critical sex pheromone component, (E)-7-dodecenyl acetate, to the major pheromone component (Z)-9-tetradecenyl acetate (Z9-14:OAc), we found that this compound was attractive to males in North Carolina, but not to males in Peru. Overall, our results suggest that both strains show rather geographic than strain-specific differences in their response to pheromone lures, and that regional sexual communication differences might cause geographic differentiation between populations.
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology (MPICE), Jena, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Unbehend
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology (MPICE), Jena, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Hänniger
authors.affiliation: Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Gissella M
authors.initials: GM
authors.lastname: Vásquez
authors.affiliation: Sección Zoología Agrícola, Estación Experimental Agroindustrial Obispo Colombres, Las Talitas, Tucumán, Argentina.
authors.forename: María Laura
authors.initials: ML
authors.lastname: Juárez
authors.affiliation: Department of Entomology, North Carolina State University, Plymouth, North Carolina, United States of America.
authors.forename: Dominic
authors.initials: D
authors.lastname: Reisig
authors.affiliation: Department of Biology, University of Western Ontario, London, Ontario, Canada.
authors.forename: Jeremy N
authors.initials: JN
authors.lastname: McNeil
authors.affiliation: Insect Behavior and Biocontrol Research Unit, United States Department of Agriculture, Gainesville, Florida, United States of America.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Meagher
authors.affiliation: Tropical Crops and Germplasm Research, United States Department of Agriculture, Mayaguez, Puerto Rico.
authors.forename: David A
authors.initials: DA
authors.lastname: Jenkins
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology (MPICE), Jena, Germany.
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology (MPICE), Jena, Germany ; Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands.
authors.forename: Astrid T
authors.initials: AT
authors.lastname: Groot
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005843:Geography; D016014:Linear Models; D008297:Male; D009656:North America; D012275:Oryza / Q000469:parasitology; D011647:Puerto Rico; D012724:Sex Attractants / Q000737:chemistry / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D013020:South America; D013045:Species Specificity; D018411:Spodoptera / Q000187:drug effects / Q000502:physiology*; D003313:Zea mays / Q000469:parasitology
chemical_list: D012724:Sex Attractants