DOI: 10.5061/dryad.w6m905r15
title: Does the munch affect the bunch? Using community science to explore insect herbivory and fruit production in an understory plant

description: Digital, community-sourced natural history records are valuable for
 understanding species attributes such as phenology and geographic
 distribution. When these records include photographs, they can also be
 analysed for individual phenotypes and species interactions to develop or
 test ecological hypotheses. Here, we use observational and experimental
 approaches to assess how insect herbivory affects reproductive success in
 a widespread forest plant, bunchberry (Cornus canadensis). We
 queried the Global Biodiversity Information Facility (GBIF) and assembled
 a dataset of 2,578 photographic records of fruiting plants. Of these, 891
 showed evidence of insect herbivory, but herbivory was not significantly
 associated with fruit production. In a field study we monitored 200 plants
 over five weeks. Herbivory was widespread (78% of plants showed insect
 feeding), but damage was generally low—only 5% of plants experienced
 herbivory ≥40% of total leaf area. No relationship was found between
 natural herbivory and fruit production. In a second study, we simulated
 high herbivory by mechanically removing 40% of leaf area in early and
 mid-season. Early-season herbivory reduced fruit production by 100%, while
 mid-season herbivory reduced fruit production by 87.3%. These
 results suggest that although high herbivory early in the season can
 substantially reduce fruiting, natural levels of herbivory exert limited
 top-down control on reproduction in bunchberry. By combining
 large-scale community-sourced records with controlled field experiments,
 this study demonstrates the value of mixed-methods approaches for testing
 ecological hypotheses and gaining insight into the processes that shape
 plant–insect interactions.
description: # Does the munch affect the bunch? Using community science to explore
 insect herbivory and fruit production in an understory plant Dataset DOI:
 [10.5061/dryad.w6m905r15](10.5061/dryad.w6m905r15) ## Description of the
 data and file structure All data is provided as CSV files. GBIFSurvey data
 was visually recorded as herbivore ID, internal and external herbivory
 intensity, and fruit count from photos accessed through the GBIF database
 ([https://doi.org/10.15468/dl.cj78zz)](https://doi.org/10.15468/dl.cj78zz)
 LongitudinalFieldSurvey data was collected over 5 weeks spanning flowering
 to fruit ripening. External and internal herbivory intensities were
 visually estimated, and fruit counts were taken at the end.
 SimulatedHerbivory data was collected as a fruit count after fruit
 ripening, following the manual defoliation of the two treatments. This was
 a 40% defoliation, performed during flowering for one treatment and during
 fruit-set for the second treatment. ### Files and variables #### File:
 LongitudinalFieldSurvey\_CumulativeHerbivory\_FruitCounts.csv
 **Description:** Cumulative herbivory intensities after a five-week survey
 of 200 ramets, with paired fruit counts. ##### Variables * herbivory: Type
 of herbivory, denoted as External, Internal (leaf mining or galling), Both
 (both external and internal herbivory), and None * intensity: Percentage
 of leaf area herbivorized at the time of fruit count, visually estimated *
 fruit_no: Number of fruits counted on the plant once ripe #### File:
 SimulatedHerbivory\_FruitCounts.csv **Description:** Number of fruits
 recorded for plants used in a simulated herbivory test with two
 defoliation timings. Missing data (blank cells) indicates that the plant
 incurred herbivory during the fruiting period and was discarded. #####
 Variables * During flowering: Number of fruits counted on the plants once
 ripe. Plants were manually defoliated of 40% of leaf area during the
 flowering period. * Early fruit-set: Number of fruits counted on the
 plants once ripe. Plants were manually defoliated of 40% of leaf area
 during the early fruit-set period. * No stimulated herbivory: Number of
 fruits counted on the plants once ripe. Plants were not manually
 defoliated. #### File:
 GBIFSurvey\_InsectID\_HerbivoryRecords\_FruitCounts.csv
 **Description:** Data visually recorded from community-science sourced
 photos, including the identity of the internal herbivore, the number of
 fruits, and the intensity of herbivory ##### Variables * herbivory: Type
 of herbivory, denoted as External, Internal (leaf mining or galling), Both
 (both external and internal herbivory), and None *
 external_intensity: Percentage of leaf area herbivorized by an external
 herbivore (does not leave a visible mine or gall), visually estimated *
 internal_intensity: Percentage of leaf area herbivorized by an internal
 herbivore (mine or gall), visually estimated * intensity: Percentage of
 leaf area herbivorized, visually estimated (external_intensity +
 internal_intensity) * fruit_no: Number of fruits counted per plant *
 place: State of observation, if observed in a location where the species
 is conservation listed as Threatened or above. Blank cell indicates the
 plant is not in a threatened range. * internal_herb_id: Visually
 identified internal herbivore. Recorded to species or in a broader group.
 Some plants include multiple IDs. Acronyms identified below: * PA:
 *Phytomyza agromyzina* * AF: *Antispila freemani* * AC: *Antispila
 cornifoliella* * PS: *Parallelodiplosis subtruncata* * LR or LF: Family
 Tortricidae moth (suspected) * CT: *Caloptilia* sp. * CO: *Coleophora* sp.
 #### File: LongitudinalFieldSurvey\_HerbivoryRecords\_FruitCounts.csv
 **Description:** Weekly data for the five-week survey of ramets. Herbivory
 was recorded weekly as visual estimates, and fruits were counted upon
 ripening. Trampled or mechanically damaged ramets were discarded. Some
 ramets were unincluded temporarily due to errors in measurement, these are
 represented as ND and the ramets were reincluded if those weeks could be
 reasonably interpolated by surrounding data. ##### Variables * Plant:
 Identifier of the plant * Herb.W1: External herbivory visually estimated
 on week 1 (18 June 2023), recorded as percentage of leaf area herbivorized
 * Mine.W1 : Internal herbivory visually estimated on week 1 (18 June
 2023), recorded as percentage of leaf area herbivorized *
 Herb.W2: External herbivory visually estimated on week 2, recorded as
 percentage of leaf area herbivorized * Mine.W2: Internal herbivory
 visually estimated on week 2, recorded as percentage of leaf area
 herbivorized * Herb.W3: External herbivory visually estimated on week 3,
 recorded as percentage of leaf area herbivorized * Mine.W3: Internal
 herbivory visually estimated on week 3, recorded as percentage of leaf
 area herbivorized * Herb.W4: External herbivory visually estimated on week
 4, recorded as percentage of leaf area herbivorized * Mine.W4: Internal
 herbivory visually estimated on week 4, recorded as percentage of leaf
 area herbivorized * Herb.W5: External herbivory visually estimated on week
 5, recorded as percentage of leaf area herbivorized * Mine.W5: Internal
 herbivory visually estimated on week 5, recorded as percentage of leaf
 area herbivorized * Berries: Count of ripe fruits on the ramet * Veg:
 Count of new vegetative shoots observed on the ramet ## Code/software Data
 was reviewed and analyzed in R Studio, but can also be reviewed in Excel
 or similar programs for other uses. It is uploaded as CSV files. R Core
 Team. (2025). R: A Language and Environment for Statistical Computing,
 [https://www.R-project.org/](https://www.R-project.org/) ## Access
 information Other publicly accessible locations of the data: *
 [https://doi.org/10.15468/dl.cj78zz](https://doi.org/10.15468/dl.cj78zz)
 Community-sourced data was recorded from iNaturalist observations accessed
 through the above occurrence download. These records are scrubbed of
 identifying information, and only the visually-collected data has been
 presented in this Dryad dataset. Data was derived from the following
 sources: * GBIF.org (10 June 2024) GBIF Occurrence Download.
 [https://doi.org/10.15468/dl.cj78zz](https://doi.org/10.15468/dl.cj78zz).