Sexual selection on receptor organ traits: younger females attract males with longer antennae
- 403 Downloads
Sexual selection theory predicts that female choice may favour the evolution of elaborate male signals. Darwin also suggested that sexual selection can favour elaborate receiver structures in order to better detect sexual signals, an idea that has been largely ignored. We evaluated this unorthodox perspective by documenting the antennal lengths of male Uraba lugens Walker (Lepidoptera: Nolidae) moths that were attracted to experimentally manipulated emissions of female sex pheromone. Either one or two females were placed in field traps for the duration of their adult lives in order to create differences in the quantity of pheromone emissions from the traps. The mean antennal length of males attracted to field traps baited with a single female was longer than that of males attracted to traps baited with two females, a pattern consistent with Darwin’s prediction assuming the latter emits higher pheromone concentrations. Furthermore, younger females attracted males with longer antennae, which may reflect age-specific changes in pheromone emission. These field experiments provide the first direct evidence of an unappreciated role for sexual selection in the evolution of sexual dimorphism in moth antennae and raise the intriguing possibility that females select males with longer antennae through strategic emission of pheromones.
KeywordsSexual selection Sex pheromones Antenna morphology Mate choice Chemical signals
T.L.J., M.R.E.S. and M.A.E. conceived the project, analysed the data and prepared the manuscript. T.L.J. collected the data.
Compliance with ethical standards
The data supporting this article have been uploaded as part of the supplementary material.
The authors declare that they have no competing interests.
Australian Research Council (DP0987360) to MAE.
- Andersson M (1994) Sexual selection. Princeton University Press, New JerseyGoogle Scholar
- Bates D, Maechler M, Bolker B, Walker S (2014) lme4: Linear mixed-effects models using Eigen and S4. R package version 11–7. URL: http://CRAN.R-project.org/package=lme4
- Greenfield MD (2002) Signalers and receivers: mechanisms and evolution of arthropod communication. Oxford University Press, OxfordGoogle Scholar
- Kuznetsova A, Brockhoff PB, Christensen RHB (2014) lmerTest: Tests in linear mixed effects models. R package version 20–20. URL: http://CRAN.R-project.org/package=lmerTest
- Lloyd JE (1979) Sexual selection in luminescent beetles. In: Blum MS, Blum NA (eds) Sexual selection and reproductive competition in insects. Academic, New York, pp 293–342Google Scholar
- Löfstedt C, Wahlberg N, Millar JG (2016) Evolutionary patterns of pheromone diversity in Lepidoptera. In: Allison JD, Carde RT (eds) Pheromone communication in moths: evolution, behavior and application. University of California Press, Oakland, pp 43–78Google Scholar
- Maynard Smith J, Harper D (2003) Animal signals. Oxford University Press, OxfordGoogle Scholar
- R Core Team (2014) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL: http://www.R-project.org/
- Skaug H, Fournier D, Nielsen A (2006) glmmADMB: Generalized linear mixed models using AD Model Builder. URL: http://glmmadmb.r-forge.r-project.org/
- Wyatt TD (2014) Pheromones and animal behavior: chemical signals and signatures. Cambridge University Press, UKGoogle Scholar