title: Effects of host plant on life-history traits in the polyphagous spider mite Tetranychus urticae.
abstract: Studying antagonistic coevolution between host plants and herbivores is particularly relevant for polyphagous species that can experience a great diversity of host plants with a large range of defenses. Here, we performed experimental evolution with the polyphagous spider mite Tetranychus urticae to detect how mites can exploit host plants. We thus compared on a same host the performance of replicated populations from an ancestral one reared for hundreds of generations on cucumber plants that were shifted to either tomato or cucumber plants. We controlled for maternal effects by rearing females from all replicated populations on either tomato or cucumber leaves, crossing this factor with the host plant in a factorial design. About 24 generations after the host shift and for all individual mites, we measured the following fitness components on tomato leaf fragments: survival at all stages, acceptance of the host plant by juvenile and adult mites, longevity, and female fecundity. The host plant on which mite populations had evolved did not affect the performance of the mites, but only affected their sex ratio. Females that lived on tomato plants for circa 24 generations produced a higher proportion of daughters than did females that lived on cucumber plants. In contrast, maternal effects influenced juvenile survival, acceptance of the host plant by adult mites and female fecundity. Independently of the host plant species on which their population had evolved, females reared on the tomato maternal environment produced offspring that survived better on tomato as juveniles, but accepted less this host plant as adults and had a lower fecundity than did females reared on the cucumber maternal environment. We also found that temporal blocks affected mite dispersal and both female longevity and fecundity. Taken together, our results show that the host plant species can affect critical parameters of population dynamics, and most importantly that maternal and environmental conditions can facilitate colonization and exploitation of a novel host in the polyphagous T. urticae, by affecting dispersal behavior (host acceptance) and female fecundity.
authors.affiliation: ISEM, Institut des Sciences de l'Evolution Montpellier, UMR 5554 (Université de Montpellier/CNRS/IRD) Place Eugène Bataillon, 34095, Montpellier Cedex 05, France.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Marinosci
authors.affiliation: CE3C, Centre for Ecology, Evolution and Environmental Sciences, Faculdade de Ciências da Universidade de Lisboa Edificio C2, 3° Piso, Campo Grande, P-1749016, Lisbon, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Magalhães
authors.affiliation: Laboratory Aquatic Biology, KU Leuven Kulak E. Sabbelaan 53, 8500, Kortrijk, Belgium.
authors.forename: Emilie
authors.initials: E
authors.lastname: Macke
authors.affiliation: INRA UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro) Campus International de Baillarguet, CS 30016, F-34988, Montferrier-sur-Lez Cedex, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Navajas
authors.affiliation: CNRS, Institut des Sciences de l'Evolution Montpellier, UMR 5554 (Université de Montpellier/CNRS/IRD) Bât. 22, Place Eugène Bataillon, 34095, Montpellier Cedex 05, France.
authors.forename: David
authors.initials: D
authors.lastname: Carbonell
authors.affiliation: ISEM, Institut des Sciences de l'Evolution Montpellier, UMR 5554 (Université de Montpellier/CNRS/IRD) Place Eugène Bataillon, 34095, Montpellier Cedex 05, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Devaux
authors.affiliation: ISEM, Institut des Sciences de l'Evolution Montpellier, UMR 5554 (Université de Montpellier/CNRS/IRD) Place Eugène Bataillon, 34095, Montpellier Cedex 05, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Olivieri
keywords: Adaptation; host shift; maternal effects; plant acceptance; plant–herbivore interactions