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Population Variability and Polyphagy in Herbivorous Insect Communities
Author(s) -
Redfearn Andrew,
Pimm Stuart L.
Publication year - 1988
Publication title -
ecological monographs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.254
H-Index - 156
eISSN - 1557-7015
pISSN - 0012-9615
DOI - 10.2307/1942633
Subject(s) - herbivore , predation , ecology , biology , uncorrelated , population , insect , parasitism , host (biology) , demography , statistics , mathematics , sociology
Our purpose in this paper is to determine how the degree of polyphagy of different herbivorous insect species affects their yearly population variability. We assembled data from three studies on herbivorous insects: on British aphids, British moths, and Canadian Macrolepidoptera. Within each data set, we compared estimates of population variability across species, and related these differences to estimates of the degree of polyphagy. The degree of polyphagy was negatively correlated or uncorrelated with population variability, i.e., highly polyphagous species have a weak tendency to be less variable than host specialists. This result lends some support to MacArthur's (1955) argument that polyphagous species may be less susceptible to fluctuating resource levels. Population variability in monophagous or oligophagous herbivorous insects may, in part, reflect variation in resource levels. However, we have not yet evaluated the possibility that the levels of predation and parasitism suffered may affect variability even more strongly.