Leaf variegation is associated with reduced herbivore damage in Hydrophyllum virginianum

Abstract

Leaf variegation refers to local regions of the upper surface of a leaf having reduced or obstructed chlorophyll, which results in whitish spots. These lighter spots may compromise the photosynthetic efficiency of a leaf, and many competing hypotheses have been put forward to explain why this patterning may be adaptive. It has been suggested that variegation is either an adaptive response to environmental conditions or a defence mechanism against herbivore damage. To test whether leaf variegation reduces herbivore damage, we first assessed the frequency of variegated and nonvariegated leaves in natural populations of the plant Hydrophyllum virginianum L., and second, measured herbivore damage to both variegated and nonvariegated leaves. We found that variegated leaves were present at high frequencies within natural populations (6%–31%) and that nonvariegated leaves sustained nearly twice the amount of damage by comparison with variegated leaves. Therefore, leaf variegation appears to be beneficial by reducing herbivore damage to leaves. These data are consistent with the fundamental prediction of the herbivory hypothesis for the benefits of leaf variegation.

Disruption of plant carotenoid biosynthesis through virus‐induced gene silencing affects oviposition behaviour of the butterfly Pieris rapae

“…, 2009). Results supporting this suggestion have also been reported in a nonmanipulative study with naturally occurring Hydrophyllum virginianum (Campitelli et al. , 2008).…”

Grey leaves in an alpine plant: a cryptic colouration to avoid attack?

“…According to this hypothesis, the magnificent leaf colouration of temperate deciduous forests can be considered as a defence commitment against insect pests. It has also been suggested that red young leaves (Lev‐Yadun & Gould, ; Archetti et al ., ), variegated adult leaves (Cahn & Harper, ; Smith, ; Campitelli et al ., ) and coloured thorns (Lev‐Yadun, , ) could be defensive signals. However, most of these studies have focused on advertised colours that are distinctive or highly visible.…”

Leaf shape variation and herbivore consumption and performance: a case study with Ipomoea hederacea and three generalists

“…In contrast to chemical and physical defenses, the evolution of leaf shape and form is often considered to have been driven by primarily abiotic factors, especially light and water availability (Givnish and Vermeij 1976;Givnish 1979;Smith 1986;Givnish 1990). While environmental conditions cannot be ignored as a selective agent on leaf morphology, several authors have suggested that herbivores may also play an important selective role in the evolution of leaf shape and specialized morphologies such as egg-mimics (Rausher 1978;Gilbert 1979;Williams and Gilbert 1981;Smith 1986;Niemala and Tuomi 1987;Givnish 1990;Brown et al 1991;Rivero-Lynch et al 1996;Campitelli et al 2008).…”