Genetic drift precluded adaptation of an insect seed predator to a novel host plant in a long-term selection experiment ...

Host specialization is considered a primary driver of the enormous diversity of herbivorous insects. Trade-offs in host use are hypothesized to promote this specialization, but they have mostly been studied in generalist herbivores. We conducted a multi-generation selection experiment to examine the...

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Bibliographic Details
Main Authors: Laukkanen, Liisa, Kalske, Aino, Muola, Anne, Leimu, Roosa, Mutikainen, Pia
Format: Article in Journal/Newspaper
Language:English
Published: ETH Zurich 2018
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Online Access:https://dx.doi.org/10.3929/ethz-b-000271725
http://hdl.handle.net/20.500.11850/271725
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Summary:Host specialization is considered a primary driver of the enormous diversity of herbivorous insects. Trade-offs in host use are hypothesized to promote this specialization, but they have mostly been studied in generalist herbivores. We conducted a multi-generation selection experiment to examine the adaptation of the specialist seed-feeding bug, Lygaeus equestris, to three novel host plants (Helianthus annuus, Verbascum thapsus and Centaurea phrygia) and to test whether trade-offs promote specialization. During the selection experiment, body size of L. equestris increased more on the novel host plant H. annuus compared to the primary host plant, Vincetoxicum hirundinaria, but this effect was not observed in other fitness related traits. In addition to selection, genetic drift caused variation among the experimental herbivore populations in their ability to exploit the host plants. Microsatellite data indicated that the level of within-population genetic variation decreased and population differentiation ... : PLoS ONE, 13 (6) ...