title: Macronutrient intake regulates sexual conflict in decorated crickets.
abstract: Sexual conflict results in a diversity of sex-specific adaptations, including chemical additions to ejaculates. Male decorated crickets (Gryllodes sigillatus) produce a gelatinous nuptial gift (the spermatophylax) that varies in size and free amino acid composition, which influences a female's willingness to fully consume this gift. Complete consumption of this gift maximizes sperm transfer through increased retention of the sperm-containing ampulla, but hinders post-copulatory mate choice. Here, we examine the effects of protein (P) and carbohydrate (C) intake on the weight and amino acid composition of the spermatophylax that describes its gustatory appeal to the female, as well as the ability of this gift to regulate sexual conflict via ampulla attachment time. Nutrient intake had similar effects on the expression of these traits with each maximized at a high intake of nutrients with a P : C ratio of 1 : 1.3. Under dietary choice, males actively regulated their nutrient intake but this regulation did not coincide with the peak of the nutritional landscape for any trait. Our results therefore demonstrate that a balanced intake of nutrients is central to regulating sexual conflict in G. sigillatus, but males are constrained from reaching the optima needed to bias the outcome of this conflict in their favour.
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.
authors.forename: J
authors.initials: J
authors.lastname: Rapkin
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.|Department of Entomology, North Carolina State University, Raleigh, NC, USA.
authors.forename: K
authors.initials: K
authors.lastname: Jensen
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Lane
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.
authors.forename: C M
authors.initials: CM
authors.lastname: House
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.|Behavior, Ecology, Evolution & Systematics Section, School of Biological Sciences, Illinois State University, Normal, IL, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Sakaluk
authors.affiliation: Centre for Ecology and Conservation, College of Life and Environmental Science, University of Exeter, Penryn, UK.
authors.forename: J
authors.initials: J
authors.lastname: Hunt
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D004032:Diet; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D006135:Gryllidae / Q000502:physiology*; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*
keywords: Gryllodes sigillatus; carbohydrate; free amino acids; protein; sexual conflict; spermatophylax