A1 Refereed original research article in a scientific journal
Do defoliating insects distinguish between symmetric and asymmetric leaves within a plant?
Authors: Mikhail Kozlov, Vitali Zverev, Elena L. Zvereva
Publisher: WILEY
Publication year: 2018
Journal: Ecological Entomology
Journal name in source: ECOLOGICAL ENTOMOLOGY
Journal acronym: ECOL ENTOMOL
Volume: 43
Issue: 5
First page : 656
Last page: 664
Number of pages: 9
ISSN: 0307-6946
DOI: https://doi.org/10.1111/een.12642
Abstract
1. Plants represent a highly heterogeneous resource for herbivores. One dimension of this heterogeneity is reflected by the within-plant variation in the leaf fluctuating asymmetry (FA), i.e. in the magnitude of the random deviations from the symmetry in leaf shape. 2. This study is the first to test experimentally the hypothesis that variation in the quality of individual leaves for defoliating insects (11 species) within a plant (seven tree and shrub species) is associated with the FA of these leaves. 3. It was demonstrated that specialist defoliators generally distinguish between nearly symmetric (low FA) and highly asymmetric (high FA) leaves, but do not distinguish between discs cut from these leaves. Low-FA leaves of Salix caprea, Salix myrsinifolia and Populus tremula were of better quality for insects than high-FA leaves, as demonstrated by both preference tests and performance trials. By contrast, high-FA leaves of Betula pubescens were of better quality for insects than low-FA leaves, whereas insects feeding on Alnus incana showed similar responses to high- and low-FA leaves. 4. It is concluded that insect herbivores can distinguish between leaves with high and low FA, and that FA may be associated with the quality of an individual leaf for insects, although the direction and strength of the effect of leaf FA on insect preference and performance vary among study systems. The ecological significance of substantial within-plant variation in leaf FA remains to be explored.
1. Plants represent a highly heterogeneous resource for herbivores. One dimension of this heterogeneity is reflected by the within-plant variation in the leaf fluctuating asymmetry (FA), i.e. in the magnitude of the random deviations from the symmetry in leaf shape. 2. This study is the first to test experimentally the hypothesis that variation in the quality of individual leaves for defoliating insects (11 species) within a plant (seven tree and shrub species) is associated with the FA of these leaves. 3. It was demonstrated that specialist defoliators generally distinguish between nearly symmetric (low FA) and highly asymmetric (high FA) leaves, but do not distinguish between discs cut from these leaves. Low-FA leaves of Salix caprea, Salix myrsinifolia and Populus tremula were of better quality for insects than high-FA leaves, as demonstrated by both preference tests and performance trials. By contrast, high-FA leaves of Betula pubescens were of better quality for insects than low-FA leaves, whereas insects feeding on Alnus incana showed similar responses to high- and low-FA leaves. 4. It is concluded that insect herbivores can distinguish between leaves with high and low FA, and that FA may be associated with the quality of an individual leaf for insects, although the direction and strength of the effect of leaf FA on insect preference and performance vary among study systems. The ecological significance of substantial within-plant variation in leaf FA remains to be explored.
UTU Research Portal