title: Experimentally induced host-shift changes life-history strategy in a seed beetle.
abstract: Expansion of the host range in phytophagous insects depends on their ability to form an association with a novel plant through changes in host-related traits. Phenotypic plasticity has important effects on initial survival of individuals faced with a new plant, as well as on the courses of evolutionary change during long-term adaptation to novel conditions. Using experimental populations of the seed beetle that evolved on ancestral (common bean) or novel (chickpea) host and applying reciprocal transplant at both larval and adult stage on the alternative host plant, we studied the relationship between the initial (plastic) phases of host-shift and the subsequent stages of evolutionary divergence in life-history strategies between populations exposed to the host-shift process. After 48 generations, populations became well adapted to chickpea by evolving the life-history strategy with prolonged larval development, increased body mass, earlier reproduction, shorter lifespan and decreased plasticity of all traits compared with ancestral conditions. In chickpea-adapted beetles, negative fitness consequences of low plasticity of pre-adult development (revealed as severe decrease in egg-to-adult viability on beans) exhibited mismatch with positive effects of low plasticity (i.e. low host sensitivity) in oviposition and fecundity. In contrast, beetles adapted to the ancestral host showed high plasticity of developmental process, which enabled high larval survival on chickpea, whereas elevated plasticity in adult behaviour (i.e. high host sensitivity) resulted in delayed reproduction and decreased fecundity on chickpea. The analysis of population growth parameters revealed significant fluctuation during successive phases of the host-shift process in A. obtectus.
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
authors.forename: Uroš
authors.initials: U
authors.lastname: Savković
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
authors.forename: Mirko
authors.initials: M
authors.lastname: ĐorĐević
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
authors.forename: Darka
authors.initials: D
authors.lastname: Šešlija Jovanović
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
authors.forename: Jelica
authors.initials: J
authors.lastname: Lazarević
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.
authors.forename: Nikola
authors.initials: N
authors.lastname: Tucić
authors.affiliation: Institute for Biological Research "Siniša Stanković", University of Belgrade, Belgrade, Serbia.|Faculty of Biology, University of Belgrade, Belgrade, Serbia.
authors.forename: Biljana
authors.initials: B
authors.lastname: Stojković
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D049628:Body Size / Q000502:physiology; D001517:Coleoptera / Q000254:growth & development / Q000502:physiology*; D007887:Fabaceae / Q000502:physiology; D007814:Larva; D000071421:Life History Traits; D008136:Longevity / Q000502:physiology; D012098:Reproduction / Q000502:physiology
keywords: Acanthoscelides obtectus Say; host-shift; life-history evolution; phenotypic plasticity; phytophagous insects; population dynamics