title: Beyond species recognition: somatic state affects long-distance sex pheromone communication.
abstract: Long-range sex pheromones have been subjected to substantial research with a particular focus on their biosynthesis, peripheral perception, central processing and the resulting orientation behaviour of perceivers. Fundamental to the research on sex attractants was the assumption that they primarily coordinate species recognition. However, especially when they are produced by the less limiting sex (usually males), the evolution of heightened condition dependence might be expected and long-range sex pheromones might, therefore, also inform about a signaller's quality. Here we provide, to our knowledge, the first comprehensive study of the role of a male's long-range pheromone in mate choice that combines chemical analyses, video observations and field experiments with a multifactorial manipulation of males' condition. We show that the emission of the long-distance sex pheromone of the burying beetle, Nicrophorus vespilloides is highly condition-dependent and reliably reflects nutritional state, age, body size and parasite load--key components of an individual's somatic state. Both, the quantity and ratio of the pheromone components were affected but the time invested in pheromone emission was largely unaffected by a male's condition. Moreover, the variation in pheromone emission caused by the variation in condition had a strong effect on the attractiveness of males in the field, with males in better nutritional condition, of older age, larger body size and bearing less parasites being more attractive. That a single pheromone is influenced by so many aspects of the somatic state and causes such variation in a male's attractiveness under field conditions was hitherto unknown and highlights the need to integrate indicator models of sexual selection into pheromone research.
authors.affiliation: Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Chemnitz
authors.affiliation: Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany.
authors.forename: Petra C
authors.initials: PC
authors.lastname: Jentschke
authors.affiliation: Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Ayasse
authors.affiliation: Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm 89081, Germany sandra.steiger@uni-ulm.de.
authors.forename: Sandra
authors.initials: S
authors.lastname: Steiger
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D005260:Female; D008297:Male; D052586:Mating Preference, Animal; D012724:Sex Attractants / Q000378:metabolism*
chemical_list: D012724:Sex Attractants
keywords: Nicrophorus vespilloides; burying beetle; chemical communication; condition dependence; mate choice; sexual selection