title: Sexual selection drives the evolution of antiaphrodisiac pheromones in butterflies.
abstract: Competition for mates has resulted in sophisticated mechanisms of male control over female reproduction. Antiaphrodisiacs are pheromones transferred from males to females during mating that reduce attractiveness of females to subsequent courting males. Antiaphrodisiacs generally help unreceptive females reduce male harassment. However, lack of control over pheromone release by females and male control over the amount transferred provides males an opportunity to use antiaphrodisiacs to delay remating by females that have returned to a receptive state. We propose a model for the evolution of antiaphrodisiacs under the influence of intrasexual selection, and determine whether changes in this signal in 11 species of Heliconius butterflies are consistent with two predictions of the model. First, we find that as predicted, male-contributed chemical mixtures are complex and highly variable across species, with limited phylogenetic signal. Second, differences in rates of evolution in pheromone composition between two major clades of Heliconius are as expected: the clade with a greater potential for male-male competition (polyandrous) shows a faster rate of divergence than the one with typically monoandrous mating system. Taken together, our results provide evidence that for females, antiaphrodisiacs can be both honest signals of receptivity (helping reduce harassment) and chastity belts (a male-imposed reduction in remating).
authors.affiliation: Section of Integrative Biology, and Brackenridge Field Laboratory, The University of Texas, Austin, Texas 78712, USA. estradac@si.edu
authors.forename: Catalina
authors.initials: C
authors.lastname: Estrada
authors.forename: Stefan
authors.initials: S
authors.lastname: Schulz
authors.forename: Selma
authors.initials: S
authors.lastname: Yildizhan
authors.forename: Lawrence E
authors.initials: LE
authors.lastname: Gilbert
mesh_terms: D000819:Animal Communication; D000818:Animals; D005075:Biological Evolution; D002080:Butterflies / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D005260:Female; D008297:Male; D052586:Mating Preference, Animal; D010675:Pheromones / Q000235:genetics*
chemical_list: D010675:Pheromones