Body size and feeding specificity: macrolepidoptera in Britain

Authors

  • Natasha Loder,

    Corresponding author
    1. Department of Entomology, The Natural History Museum, Cromwell Road, London SW7 5BD
    2. Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN
      10 Myddleton Road, Wood Green, London N22 4NS.
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    • 10 Myddleton Road, Wood Green, London N22 4NS.

  • Kevin J. Gaston,

    1. Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN
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  • Philip H. Warren,

    1. Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN
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  • Henry R. Arnold

    1. Biological Records Centre, Institute of Terrestrial Ecology, Monks Wood, Abbots Ripton, Cambridgeshire PE17 2LS
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10 Myddleton Road, Wood Green, London N22 4NS.

Abstract

Within a geographic assemblage, large-bodied species of macrolepidopteran moths tend, on average, to be less host-specific than small-bodied. Five possible explanations for this pattern are identified, based respectively on (i) phylogenetic relationships between species, (ii) latitudinal gradients in body size and feeding specificity, (iii) the relationship between range size and body size, (iv) larger body size as a buffer from environmental variation, and (v) the relationship between endophagous host associations and small body size. These mechanisms are tested using data for British macrolepidoptera and also evaluated using evidence from the literature at large. Although some of their assumptions are found to be justified, there is no significant support for any single mechanism. This lack of evidence for previously proposed mechanisms is discussed in the light of a recently proposed alternative explanation which combines theories of host quality and host defence mechanisms.

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