DOI: 10.5061/dryad.c3v62
title: Data from: Manifold influences of phylogenetic structure on a plant-herbivore network

description: Ecologists are increasingly aware of the interplay between evolutionary
 history and ecological processes in shaping current species interaction
 patterns. The inclusion of phylogenetic relationships in studies of
 species interaction networks has shown that closely related species
 commonly interact with sets of similar species. Notably, the degree of
 phylogenetic conservatism in antagonistic ecological interactions is
 frequently stronger among species at lower trophic levels than among those
 at higher trophic levels. One hypothesis that accounts for this asymmetry
 is that competition among consumer species promotes resource partitioning
 and offsets the maintenance of dietary similarity by phylogenetic inertia.
 Here, we used a regional plant-herbivore network comprised of Asteraceae
 species and flower-head endophagous insects to evaluate how the strength
 of phylogenetic conservatism in species interactions differs between the
 two trophic levels. We also addressed whether the asymmetry in the
 strength of the phylogenetic signal between plants and animals depends on
 the overall degree of relatedness among the herbivores. We show that,
 beyond the previously reported compositional similarity, closely related
 species also share a greater proportion of counterpart phylogenetic
 history, both for resource and consumer species. Comparison of the
 patterns found in the entire network with those found in subnetworks
 composed of more phylogenetically restricted groups of herbivores provides
 evidence that resource partitioning occurs mostly at deeper phylogenetic
 levels, so that a positive phylogenetic signal in antagonist similarity is
 detectable even between closely related consumers in monophyletic
 subnetworks. The asymmetry in signal strength between trophic levels is
 most apparent in the way network modules reflect resource phylogeny, both
 for the entire network and for subnetworks. Taken together, these results
 suggest that evolutionary processes, such as phylogenetic conservatism and
 independent colonization history of the insect groups may be the main
 forces generating the phylogenetic structure observed in this particular
 plant–herbivore network system.
description: Phylogenetic tree of the
 Asteraceae speciesPlant phylogeny was
 constructed by combining the information from a composite tree of the
 Asteraceae family (Funk et al. 2009) for most genera, with taxonomy
 serving as a surrogate for phylogenetic relationships of nodes for which
 no information was available. When even the taxonomy was unable to provide
 relationships, unresolved nodes were left as polytomies. Species were also
 attached as polytomies deriving from each genus.ast.nexPhylogenetic tree of the endophagous insect speciesThis is an informal tree constructed by taxonomic substitution (sensu Bininda-Edmonds et al. 2001) of the available phylogenetic information for the insect species collected in our study. Starting with a purely taxonomic tree, we added information on the relationships between taxa whenever available (Supplementary material 1 Figure A1).endo.nexAsteraceae-Herbivore interaction networkAssociations between Asteraceae and flower-head endophagous insects were assessed quantitatively in 20 remnants of Cerrado vegetation in southeastern Brazil (Almeida-Neto et al. 2011).The sampled sites were spaced from 0.6 to 41.4 km apart (mean distance = 16.3 km), at elevations ranging from 600 to 950 m. Plants and insects were sampled from April to May 2003. The sampling design consisted of 15 transects of 30m × 5m, randomly allocated in relation to the edge of the areas. We sampled flower heads from at least 20 individuals of each Asteraceae species, collecting about 80 mL of flower-heads per individual plant whenever available. In the laboratory, the flower-head samples were kept in plastic containers covered with a mesh lid. Adult herbivore emergence was checked at least weekly for a period of two months. We spent about four person-hours collecting flower-heads in each period and site. Further information on sampling, vegetation, and studied areas can be found in Almeida-Neto et al. (2010, 2011). For the purpose of this study, both species and their interactions were integrated into a single regional plant-herbivore network, depicting the presence or absence of interactions between each plant-herbivore pair. We only included in the regional interaction network the plant and insect species that occurred in at least five (25%) of the sampled areas. By constructing the network in this way, we aimed to minimize the effect of spatial mismatch on the structure of plant-herbivore interactions. Among the 1210 plant-herbivore pairs included in our network, only 12 do not co-occur in at least one site.interaction_network.txt