Trichome production and variation in young plant resistance to the specialist insect herbivore Plutella xylostella among natural populations of Arabidopsis lyrata

• The strength of plant-herbivore interactions varies spatially and through plant ontogeny, which may result in variable selection on plant defenses against herbivory both among populations and among different life-history stages. The perennial herb Arabidopsis lyrata occurs in a trichome-producing and a glabrous morph, and previous work has shown that glabrous plants tend to receive more damage than trichome-producing plants. In this study, we quantified oviposition preference and larval feeding by P. xylostella on very young A. lyrata (5-6 weeks old), originating from twelve natural populations, six from Sweden and six from Norway. Six of the populations (three from each region) were polymorphic for trichome production and allowed a comparison of resistance against P. xylostella between the glabrous and the trichome-producing morph at a stage when trichome density is low in trichome-producing plants. There was considerable variation among populations in the number of eggs received and the proportion of leaf area consumed, but not between regions (Sweden and Norway) or trichome morphs. Rosette size explained a significant portion of the variation in oviposition and larval feeding. The results demonstrate that among-population variation in resistance to insect herbivory can also be detected among very young individuals of the perennial herb A. lyrata. They further suggest that trichome densities are too low at this developmental stage to contribute to resistance, and that the observed among-population variation in resistance is related to differences in other plant traits.

Ämnesord

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Nyckelord

oviposition

larval feeding

ontogeny

plant defense

trichome density

Biology with specialization in Ecological Botany

Biologi med inriktning mot ekologisk botanik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)