title: Insect mating signal and mate preference phenotypes covary among host plant genotypes.
abstract: Sexual selection acting on small initial differences in mating signals and mate preferences can enhance signal-preference codivergence and reproductive isolation during speciation. However, the origin of initial differences in sexual traits remains unclear. We asked whether biotic environments, a source of variation in sexual traits, may provide a general solution to this problem. Specifically, we asked whether genetic variation in biotic environments provided by host plants can result in signal-preference phenotypic covariance in a host-specific, plant-feeding insect. We used a member of the Enchenopa binotata species complex of treehoppers (Hemiptera: Membracidae) to assess patterns of variation in male mating signals and female mate preferences induced by genetic variation in host plants. We employed a novel implementation of a quantitative genetics method, rearing field-collected treehoppers on a sample of naturally occurring replicated host plant clone lines. We found remarkably high signal-preference covariance among host plant genotypes. Thus, genetic variation in biotic environments influences the sexual phenotypes of organisms living on those environments in a way that promotes assortative mating among environments. This consequence arises from conditions likely to be common in nature (phenotypic plasticity and variation in biotic environments). It therefore offers a general answer to how divergent sexual selection may begin.
authors.affiliation: Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee, Lapham Hall, 3209 North Maryland Avenue, Milwaukee, Wisconsin, 53201; Current Address: Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, Faculté de Sciences et Techniques, Avenue Monge, Parc Grandmont, 37200, Tours, France. darren.rebar@univ-tours.fr.
authors.forename: Darren
authors.initials: D
authors.lastname: Rebar
authors.forename: Rafael L
authors.initials: RL
authors.lastname: Rodríguez
mesh_terms: D000819:Animal Communication; D000818:Animals; D005075:Biological Evolution; D058448:Biota; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006430:Hemiptera / Q000235:genetics / Q000502:physiology*; D008297:Male; D052586:Mating Preference, Animal; D010641:Phenotype; D010944:Plants / Q000145:classification*
keywords: Divergence; Fisherian selection; indirect genetic effects; plant-insect interaction; runaway; vibrational communication