DOI: 10.5061/dryad.7h44j106f
title: Foliar herbivory pushes plant individuals towards the periphery of a plant-floral visitor interaction network

description: Indirect interactions are major forces structuring communities. In
 terrestrial ecosystems, changes in plant traits caused by herbivory have
 the potential to mediate cascades of indirect interactions that can
 profoundly affect community structure. We have begun to understand the
 mechanisms behind indirect effects mediated by trait changes in plants,
 but we still know little about how these interaction-level mechanisms
 affect higher levels of community organization, in particular network
 structure, and how this is dependent on community context. In this study,
 we aimed to understand how herbivory affects floral traits, flower
 visitation and the position of plant individuals in a plant-flower visitor
 network. To do this, we assessed the natural incidence of leaf and
 flowerhead herbivory in a tropical shrub and tested how it affects
 flowerhead density and the interactions between flowers and Lepidoptera,
 Hymenoptera, and Diptera at the pairwise and network levels. We also
 tested how the local density of conspecific plants adds context dependency
 to these interactions by affecting both herbivory and flowerhead
 visitation in focal plants. Increased leaf herbivory reduced flowerhead
 density per plant and indirectly reduced flowerhead visitation by
 Hymenoptera, while for Diptera direct effects of herbivory were important
 and Lepidoptera were not affected. At the network level, plants with more
 flowerheads were more connected and central. By reducing flowerhead
 density, leaf herbivory caused individual plants to lose centrality,
 becoming less connected and therefore peripheral in the plant-flower
 visitor network. This dynamic is context dependent since increased plant
 conspecific local density reduced leaf herbivory in the focal plant and
 indirectly benefited its flowerhead density, flowerhead visitation and
 network centrality. Synthesis: We demonstrate how the effects of herbivory
 on a key plant trait can cascade to shape the interactions between
 individual plants and their flower visitors and how the indirect effects
 between herbivores and pollinators can modulate the structure of
 interaction networks in plant-based ecosystems.
description: # Foliar herbivory pushes plant individuals towards the periphery of a
 plant-floral visitor interaction network Dataset DOI:
 [10.5061/dryad.7h44j106f](10.5061/dryad.7h44j106f) ## Description of the
 data and file structure In December 2015, we marked all *T. adenantha*
 individuals found along a 2.5 km trail at the Reserva Biológica Municipal
 da Serra do Japi, Jundiaí, São Paulo, Brazil (23°14'01.3"S
 46°56'09.2"W), totaling 150 plants. Of these, 61 either died or
 did not flower during the study, leaving 89 individuals included in the
 analysis. Between December 2015 and May 2016, we randomly sampled plants
 with at least one reproductive branch (approximately five individuals per
 day, totaling 15 per month over 21 sampling days). Each plant served as an
 independent unit for data collection, which included: - Observation of
 flowerhead visitation (1h observation of a single focal reproductive
 branch per plant) - Flowerhead density (total flowerheads in anthesis per
 plant) - Flowerhead herbivory (estimated for all flowerheads in anthesis
 on the focal branch per plant) - Leaf herbivory (estimated for all
 expanded leaves on the focal branch and 30 randomly selected fully
 expanded leaves from other branches per plant) - Nearby density of
 conspecific plants (number of all the reproductive individuals within a 3
 m radius of the focal plant) - Plant size (the length of the longest
 branch per plant) Each plant was sampled only once. For interaction
 network analysis, we included only those plants that interacted with
 flowerhead visitors during observation (41 out of the 89 sampled). For a
 detailed description of the sampling methods and effects, see Rezende et
 al. (2025). Foliar herbivory pushes plant individuals towards the
 periphery of a plant-floral visitor interaction network. Journal of
 Ecology. ### Files and variables DATA & FILE OVERVIEW 1. File List: *
 Rezendeetal_JEcol_dataset.txt - File containing data on Trichogoniopsis
 adenantha herbivory and flowerhead visitation (.txt file). *
 Rezendeetal_JEcol_dataset.csv - File containing data on Trichogoniopsis
 adenantha herbivory and flowerhead visitation (CSV file). (NOTE: the two
 data files above are identical and are provided in different formats to
 maximise accessibility) * Rezendeetal_JEcol_Rscript_network.R - R
 environment file containing code for the network analysis (See Rezende et
 al (2025). Foliar herbivory pushes plant individuals towards the periphery
 of a plant-floral visitor interaction network. Journal of Ecology) *
 Rezendeetal_JEcol_Rscript_SEM.R - R environment file containing code for
 the structural equation modelling (See Rezende et al (2025). Foliar
 herbivory pushes plant individuals towards the periphery of a plant-floral
 visitor interaction network. Journal of Ecology) 2. Relationship between
 files, if important: N/A 3. Additional related data collected that was not
 included in the current data package: N/A 4. Are there multiple versions
 of the dataset? No METHODOLOGICAL INFORMATION 1. Description of methods
 used for collection/generation of data: See Rezende et al (2025). Foliar
 herbivory pushes plant individuals towards the periphery of a plant-floral
 visitor interaction network. Journal of Ecology. 2. Methods for processing
 the data: See Rezende et al (2025). Foliar herbivory pushes plant
 individuals towards the periphery of a plant-floral visitor interaction
 network. Journal of Ecology. 3. Instrument- or software-specific
 information needed to interpret the data: See Rezende et al (2025). Foliar
 herbivory pushes plant individuals towards the periphery of a plant-floral
 visitor interaction network. Journal of Ecology. 4. Standards and
 calibration information, if appropriate: N/A 5. Environmental/experimental
 conditions: N/A 6. Describe any quality-assurance procedures performed on
 the data: N/A 7. People involved with sample collection, processing,
 analysis and/or submission: Gabriela Gomes and João Suzigan helped with
 the field work. André V.L. Freitas, Viviane Ferro, João Robazzi and Sidnei
 Mateus helped with flowerhead visitor identification. Karoline Ceron
 helped with the R code for the interaction network figure. DATA-SPECIFIC
 INFORMATION FOR: Rezendeetal_JEcol_dataset.txt 1. Number of variables: 47
 2. Number of cases/rows: 90 3. Variable List: * plant: individual plant
 identity * month: sampling year and month * hour: sampling hour interval *
 conspecific_neighbors: number of reprodutive plants neighboring the focal
 plant * plant_length_cm: length of the longest branch of the plant in
 centimeters (cm) * reproductive_branches: number of reproductive branches
 of the plant * plant_flowerheads: number of receptive flowerheads on the
 plant * branch_flowerheads: number of receptive flowerheads on the focal
 branch * damg_flowerheads: proportion of damaged flowerheads on the focal
 branch * leaves: number of leaves sampled on the plant * damg_leaves:
 proportion of damaged leaves regardless of herbivore guild *
 damg_leaves_category: categorization of plants into less damaged
 (minor_damage: * damg_leaves less than or equal to 0.55) and more damaged
 (major_damage: damg_leaves greater than 0.55) * damg_ps: proportion of
 damaged leaves by piercer-suckers * damg_ch: proportion of damaged leaves
 by chewers * damg_mn: proportion of damaged leaves by miners *
 damg_only_ps: proportion of damaged leaves only by piercer-suckers *
 damg_only_ch: proportion of damaged leaves only by chewers * damg_only_mn:
 proportion of damaged leaves only by miners * damg_only_ps_ch: proportion
 of damaged leaves only by piercer-suckers and chewers * damg_only_ps_mn:
 proportion of damaged leaves only by piercer-suckers and miners *
 damg_only_ch_mn: proportion of damaged leaves only by chewers and miners *
 damg_only_ps_ch_mn: proportion of damaged leaves only by piercer-suckers,
 chewers, and miners * visit_total: number of flowerhead visits regardless
 of insect order * visit_dip: number of flowerhead visits by all insects of
 the order Diptera * visit_hym: number of flowerhead visits by all insects
 of the order Hymenoptera * visit_lep: number of flowerhead visits by all
 insects of the order Lepidoptera * visit_lep_ni: number of flowerhead
 visits by all insects identified only up to the order Lepidoptera *
 visit_hym_ni: number of flowerhead visits by all insects identified only
 up to the order Hymenoptera * visit_dip_ni: number of flowerhead visits by
 all insects identified only up to the order Diptera *
 visit_nymphalidae_ni: number of flowerhead visits by all insects
 identified only up to the family Nymphalidae * visit_halictidae_ni: number
 of flowerhead visits by all insects identified only up to the family
 Halictidae * vists_aeria_olena_olena: number of flowerhead visits by Aeria
 olena olena * vists_episcada_sylvo: number of flowerhead visits by
 Episcada sylvo * vists_eumenogaster_sp: number of flowerhead visits by
 Eumenogaster sp * vists_heterosais_edessa: number of flowerhead visits by
 Heterosais_edessa * vists_ithomia_drymo: number of flowerhead visits by
 Ithomia drymo * vists_nridela_acroxantha: number of flowerhead visits by
 Nridela acroxantha * vists_pseudoscada_erruca: number of flowerhead visits
 by Pseudoscada erruca * vists_rhynchopyga_sp: number of flowerhead visits
 by Rhynchopyga sp * vists_sphecopsyche_sp: number of flowerhead visits by
 Sphecopsyche sp * vists_plebeia_droryana: number of flowerhead visits by
 Plebeia droryana * vists_pseudaugochlora_sp: number of flowerhead visits
 by Pseudaugochlora sp * vists_trigona_hyalinata: number of flowerhead
 visits by Trigona hyalinata * vists_syrphidae_sp1: number of flowerhead
 visits by Syrphidae sp1 * vists_syrphidae_sp2: number of flowerhead visits
 by Syrphidae sp2 * vists_syrphidae_sp3: number of flowerhead visits by
 Syrphidae sp3 * vists_syrphidae_sp4: number of flowerhead visits by
 Syrphidae sp4 4. Missing data codes: N/A 5. Specialized formats or other
 abbreviations used: N/A ## Code/software We performed all the network and
 statistical analyses using the R Environment (version 4.0.4; R Core Team
 2021). Specifically, we used the following R package: - igraph R package
 (version 2.0.3; Csardi & Nepusz, 2006):  to build the interaction
 network and identified the shortest network distance - stats R package
 (version 4.4.1),  prcomp function: to perform the Principal Component
 Analysis (PCA) - piecewiseSEM R package (version 2.3.0.1, Lefcheck, 2016):
 to perform the Structural Equation Modelling (SEM) analysis - lme4 R
 package (version 1.1-35.4; Bates et al., 2015):  to build the Generalised
 Linear Mixed Models (GLMMs) - DHARMa diagnostics (Hartig, 2016) and vif
 function of the car R package (version 3.1-2):  to assess base model
 suitability We provide the commented R scripts for Structural Equation
 Modelling (SEM) and Interaction Network analysis at the
 Rezendeetal_JEcol_Rscript_SEM.R and Rezendeetal_JEcol_Rscript_network.R.,
 respectively. For a detailed description of the data analysis, see Rezende
 et al. (2025). Foliar herbivory pushes plant individuals towards the
 periphery of a plant-floral visitor interaction network. Journal of
 Ecology.