PATTERNS OF DIVERSIFICATION IN PHYTOPHAGOUS INSECTS

phytophage life histories and feeding modes, full characterization of host use evolution
will require, in addition to hypothesis tests in particular groups, the estimation of relative
frequencies of alternative evolutionary patterns across a broad sampling of lineages. Our
emphasis here is on the latter approach. A complete catalog is no longer feasible, but we
have made a concerted and continuing effort to compile as many phylogenetic studies of
phytophagous insect groups as possible. These are entered into a database which at this
writing contained over 1000 entries, many of which were obtained from the Zoological
Record database. Our analyses and conclusions are based chiefly on approximately 200
of these reports which contain both a phylogenetic tree and information on host plant use.
Many of the phylogenies are based on DNA sequences, while for others the chief
evidence is morphology. This data base, intended as a community resource to promote
further synthesis, is available at www.chemlife.umd.edu/entm/mitterlab, as are the data
compilations and other supplementary materials mentioned in the text. Our nomenclature
follows Angiosperm Phylogeny Group (2003; hereafter APGII) for angiosperm families
and higher groups, and Smith et al. (2006) for ferns.
Conservatism of Host-Plant Use
Full understanding of the influence of evolutionary history on insect/plant
associations will require a broad accounting of the degree to which the different
dimensions of the feeding niches of phytophagous insects are phylogenetically
conserved. Much evidence on some aspects of this question has accumulated in the past
decade.
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