title: Fitness costs of thermal reaction norms for wing melanisation in the large white butterfly (Pieris brassicae).
abstract: The large white butterfly, Pieris brassicae, shows a seasonal polyphenism of wing melanisation, spring individuals being darker than summer individuals. This phenotypic plasticity is supposed to be an adaptive response for thermoregulation in natural populations. However, the variation in individuals' response, the cause of this variation (genetic, non genetic but inheritable or environmental) and its relationship with fitness remain poorly known. We tested the relationships between thermal reaction norm of wing melanisation and adult lifespan as well as female fecundity. Butterflies were reared in cold (18°C), moderate (22°C), and hot (26°C) temperatures over three generations to investigate variation in adult pigmentation and the effects of maternal thermal environment on offspring reaction norms. We found a low heritability in wing melanisation (h(2) =0.18). Rearing families had contrasted thermal reaction norms. Adult lifespan of males and females from highly plastic families was shorter in individuals exposed to hot developmental temperature. Also, females from plastic families exhibited lower fecundity. We did not find any effect of maternal or grand-maternal developmental temperature on fitness. This study provides new evidence on the influence of phenotypic plasticity on life history-traits' evolution, a crucial issue in the context of global change.
authors.affiliation: Muséum National d'Histoire Naturelle, UMR 7205 Institut Systématique Evolution Biodiversité, Paris, France ; INRA, Equipe Ecotoxicologie et Qualité des Milieux Aquatiques, UMR 985 Ecologie et Santé des Ecosystèmes, INRA-Agrocampus, Rennes, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Chaput-Bardy
authors.affiliation: Muséum National d'Histoire Naturelle, UMR 7205 Institut Systématique Evolution Biodiversité, Paris, France ; Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: Simon
authors.initials: S
authors.lastname: Ducatez
authors.affiliation: Muséum National d'Histoire Naturelle, UMR 7205 Institut Systématique Evolution Biodiversité, Paris, France ; Station d'Ecologie Expérimentale du CNRS à Moulis, CNRS USR 2936, Moulis, France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Legrand
authors.affiliation: Muséum National d'Histoire Naturelle, UMR 7205 Institut Systématique Evolution Biodiversité, Paris, France ; Station d'Ecologie Expérimentale du CNRS à Moulis, CNRS USR 2936, Moulis, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Baguette
mesh_terms: D000818:Animals; D002080:Butterflies / Q000502:physiology*; D005260:Female; D008297:Male; D010641:Phenotype; D014921:Wings, Animal / Q000502:physiology*