DOI: 10.5061/dryad.1vhhmgqzg
title: Data from: Honey bees (Apis mellifera) modify plant-pollinator network structure, but do not alter wild species’ interactions

description: Honey bees (Apis mellifera) are widely used for honey production and crop
 pollination, raising concern for wild pollinators, as honey bees
 may compete with wild pollinators for floral resources. The first
 sign of competition, before changes appear in wild pollinator
 abundance or diversity, may be changes to wild pollinator interactions
 with plants. Such changes for a community can be measured by
 looking at changes to metrics of resource use overlap in
 plant-pollinator interaction networks. Studies of honey bee
 effects on plant-pollinator networks have usually not distinguished
 whether honey bees alter wild pollinator interactions, or if they
 merely alter total network structure by adding their own
 interactions. To test this question, we experimentally introduced
 honey bees to a Canadian grassland and measured
 plant-pollinator interactions at varying distances from the
 introduced hives. We found that honey bees increased the network
 metrics of pollinator and plant functional complementarity
 and decreased interaction evenness. However, in networks
 constructed from just wild pollinator interactions, honey bee
 abundance did not affect any of the metrics calculated. Thus, all
 network structural changes to the full network (including
 honey bee interactions) were due only to honey bee-plant
 interactions, and not to honey bees causing changes in wild
 pollinator-plant interactions. Given widespread and
 increasing use of honey bees, it is important to establish
 whether they affect wild pollinator communities. Our results
 suggest that honey bees did not alter wild pollinator
 foraging patterns in this system, even in a year that was drier
 than the 20-year average.
description: In southern Alberta, Canada we established eighteen 30 x 2 m
 transects at 100 m, 500 m, and 5000 m distances on either side of each of
 3 clusters of honey bee hives for a total of six replicates. Between May
 28 and August 28, 2019, observers visited each transect and surveyed
 insect flower visitation almost once per week for a total of 10 collection
 rounds. All insects that visibly contacted the anthers or stigma of open
 flowers were collected with a hand net and placed in labelled individual
 vials, frozen, and identified to species in the lab. Associated flowers
 were identified to species. The data were entered in Excel and processed
 and cleaned in R/Rstudio. The data provided includes
 interaction data from nineteen transects (originally 18 but F5000 was
 replaced with G5000 mid-season). Interactions are recorded between
 pollinators and plants and the dataset also includes flower species
 abundance data for each transect sampled. Additionally, transect locations
 and locations of the bee hives placed are included. The
 data provided also includes measured functional trait data from bees
 caught from the hand-caught dataset. Later, some of the
 pinned insect specimens' body sizes were measured and contributed to
 the paper: "Pollinator intraspecific body size variation and
 sociality influence their interactions with plants". 2024. Functional
 Ecology. Authored by Peralta, Guadalupe; Resasco, Julian; Worthy, Sydney;
 Frost, Carol; Guevara, Angie; Manning, Isabella; Cagnolo, Luciano; Burkle,
 Laura. To take body size measurements, the selected
 specimens were photographed from the dorsal side with a Nikon COOLPIX 8400
 Digital Camera mounted on an OLYMPUS SZX16 stereo microscope. A ruler was
 placed adjacent to and in the same plane as the insect’s dorsal surface
 during photography. The images were then imported into ImageJ, calibrated
 using the ruler as a scale bar, and measured using the line tool to
 manually delineate the intertegular distance, which is the distance
 spanning between the wing bases. Only intergegular distances were analyzed
 in the above paper. However, other distances measured for some specimens
 included: thorax length (as viewed dorsally and measured along the
 midpoint), head width, head length, abdomen length, and body
 length.
description: Microsoft Excel is needed to open the data files and R is needed
 to analyze the data.
description: # Honey bees (Apis mellifera) modify plant-pollinator network structure,
 but do not alter wild species interactions --- ## Abstract Honey bees
 (Apis mellifera) are widely used for honey production and crop
 pollination, raising concern for wild pollinators, as honey bees may
 compete with wild pollinators for floral resources. The first sign of
 competition, before changes appear in wild pollinator abundance or
 diversity, may be changes to wild pollinator interactions with plants.
 Such changes for a community can be measured by looking at changes to
 metrics of resource use overlap in plant-pollinator interaction networks.
 Studies of honey bee effects on plant-pollinator networks have usually not
 distinguished whether honey bees alter wild pollinator interactions, or if
 they merely alter total network structure by adding their own
 interactions. To test this question, we experimentally introduced honey
 bees to a Canadian grassland and measured plant-pollinator interactions at
 varying distances from the introduced hives. We found that honey bees
 increased the network metrics of pollinator and plant functional
 complementarity and decreased interaction evenness. However, in networks
 constructed from just wild pollinator interactions, honey bee abundance
 did not affect any of the metrics calculated. Thus, all network structural
 changes to the full network (including honey bee interactions) were due
 only to honey bee-plant interactions, and not to honey bees causing
 changes in wild pollinator-plant interactions. Given widespread and
 increasing use of honey bees, it is important to establish whether they
 affect wild pollinator communities. Our results suggest that honey bees
 did not alter wild pollinator foraging patterns in this system, even in a
 year that was drier than the 20-year average. ## Summary of methods In
 southern Alberta, Canada we established eighteen 30 x 2 m transects at 100
 m, 500 m, and 5000 m distances on either side of each of 3 clusters of
 honey bee hives for a total of six replicates. Between May 28 and August
 28, 2019, observers visited each transect and surveyed insect flower
 visitation almost once per week for a total of 10 collection rounds. All
 insects that visibly contacted the anthers or stigma of open flowers were
 collected with a hand net and placed in labelled individual vials, frozen,
 and identified to species in the lab. Associated flowers were identified
 to species. The data were entered in Excel and processed and cleaned in R
 / Rstudio. The data provided includes interaction data from nineteen
 transects (originally 18 but F5000 was replaced with G5000 mid-season).
 Interactions are recorded between pollinators and plants and the dataset
 also includes flower species abundance data for each transect sampled.
 Additionally, transect locations and locations of the bee hives placed are
 included. A total of 281 pollinator species and 37 plant species were
 identified in 1,814 interactions. Later, some of the pinned insect
 specimens' body sizes were measured and contributed to the paper:
 "Pollinator intraspecific body size variation and sociality influence
 their interactions with plants". 2024. Functional Ecology. Authored
 by Peralta, Guadalupe; Resasco, Julian; Worthy, Sydney; Frost, Carol;
 Guevara, Angie; Manning, Isabella; Cagnolo, Luciano; Burkle, Laura. To
 take body size measurements, the selected specimens were photographed from
 the dorsal side with a Nikon COOLPIX 8400 Digital Camera mounted on an
 OLYMPUS SZX16 stereo microscope. A ruler was placed adjacent to and in the
 same plane as the insect’s dorsal surface during photography. The images
 were then imported into ImageJ, calibrated using the ruler as a scale bar,
 and measured using the line tool to manually delineate the intertegular
 distance, which is the distance spanning between the wing bases. Only
 intergegular distances were analyzed in the above paper. However, other
 distances measured for some specimens included: thorax length (as viewed
 dorsally and measured along the midpoint), head width, head length,
 abdomen length, and body length. ## Description of the data and file
 structure ## Location information: The data were obtained on the
 University of Alberta's Mattheis Research Ranch and surrounding land
 administered by Eastern Irrigation District, which is in mixedgrass
 prairie rangeland near the town of Brooks, Alberta, Canada; GPS locations
 of sampling coordinates are listed in the sheet called "Transect
 Locations 2019" along with the number of collection rounds (Each
 number corresponds to one sampling pass through all the transects that
 were possible to sample in that round; one week of sampling). The bee
 hives did not have a collection round and so have NA in their cell. Data
 is in Excel spreadsheet format. ## Column header titles for each Excel
 spreadsheet tab: ### Transect Locations 2019 Longitude - Longitude of the
 transect or bee hive cluster. Measured with Garmin handheld GPS. Latitude
 - Latitude of the transect or bee hive cluster. Measured with Garmin
 handheld GPS. Transect - Name of the transect or bee hive cluster. The
 number at the end of each name refers to the number of hives in the bee
 hive cluster, or the distance of the transect from the nearest bee hive
 cluster (in metres), respectively. Total Hand-Caught Collections - Number
 of times this transect was sampled in 2019 by netting flower visitors
 along the 30-m x 2-m transect for 30 min by 2 observers. ### Transect
 Flower Counts 2019 Date_DMY - Date that the transect was sampled by Date,
 Month, Year Collection - This variable is another way of recording the
 date, with 1 corresponding to the first sampling date, 2 corresponding to
 the second sampling date, etc., throughout the whole season. Season -
 Early, Mid, or Late "season". Rationale for these divisions
 based on abundance of honey bees (see Worthy et al., 2023, PLOS ONE )
 Transect_ID - Transect name. The number at the end of each name refers to
 the distance of the transect from the nearest bee hive cluster (in
 metres), though some transects named as 5000 were more than 5000 m from
 the nearest hive cluster. Treatment - Distance of the transect from the
 nearest hive cluster. For some t5000 replicates, the transect was greater
 than 5000 m from the nearest hive cluster. Plant_ID - Plant species or
 morphospecies. Each row represents an individual plant found on the
 transect with flowers. Flower_count - Number of flowers counted (or
 estimated) for that plant individual. ### Interaction Data 2019 Date_DMY -
 Date that the transect was sampled by Date, Month, Year Collection - This
 variable is another way of recording the date, with 1 corresponding to the
 first sampling date, 2 corresponding to the second sampling date, etc.,
 throughout the whole season. Coll_round - Each number corresponds to one
 sampling pass through all the transects that were possible to sample in
 that round. Season - Early, Mid, or Late "season". Rationale for
 these divisions based on abundance of honey bees (see Worthy et al., 2023,
 PLOS ONE) Transect_ID - Transect name. The number at the end of each name
 refers to the distance of the transect from the nearest bee hive cluster
 (in metres), though some transects named as 5000 were more than 5000 m
 from the nearest hive cluster. Treatment - Distance of the transect from
 the nearest hive cluster. For some t5000 replicates, the transect was
 greater than 5000 m from the nearest hive cluster. Temp_C - Temperature
 (degrees C). Measured with a handheld Brunton Sherpa before starting to
 sample the transect. Wind_km - Wind speed (km/hr). Measured with a
 handheld Brunton Sherpa before starting to sample the transect.
 Pressure_kPa - Pressure (kPa). Measured with a handheld Brunton Sherpa
 before starting to sample the transect. Insect_ID - Unique ID number for
 this insect. Number composed of the date on which the insect was collected
 visiting a flower, a dash, and then a number representing what number
 individual this was. E.g., -3 means the third insect collected at that
 transect on that date. Plant_ID - Plant species name Species_Comm - Insect
 species group common name Species_ID - Insect species or morphospecies
 name. Genus names are capitalized. Specific epithets are not capitalized.
 When a name contains two capitalized names, that insect genus ID was
 undecided between those two genera. NA refers to insects that were
 observed but unidentifiable (usually because they escaped the net).
 Order.group - Latin name for species group (with groupings at different
 taxonomic levels but generally at the level of Order) Plant_no - Number
 corresponding to that plant species (for graphing and analysis) Species_no
 - Number corresponding to that insect species (for graphing and analysis)
 ### Measurements Insect_ID - Unique (within a transect) ID number for this
 insect. Number composed of the date on which the insect was collected
 visiting a flower, a dash, and then a number representing what number
 individual this was. E.g., -3 means the third insect collected at that
 transect on that date. Species_ID - Insect species or morphospecies name.
 Genus names are capitalized. Specific epithets are not capitalized. When a
 name contains two capitalized names, that insect genus ID was undecided
 between those two genera. Included in Peralta et al 2024 - "Yes"
 or "No", indicating whether the thorax width measurement was
 included in the data set analyzed in Peralta et al 2024 (Functional
 Ecology) or not Thorax Width (mm) - Thorax width (intertegular distance)
 measured as described above in the methods, in mm. Thorax length (mm) -
 The longitudinal measurement of the thorax from the point where it meets
 the head to where it meets the abdomen, in mm. VNA (Value Not Available)
 indicates that this value was not measured. Head width (mm) - Maximum
 width of the head (lateral body axis, viewed dorsally), in mm. VNA (Value
 Not Available) indicates that this value was not measured. Head length
 (mm) - The distance from the anterior-most point of the head to the
 posterior-most point (viewed dorsally), in mm. VNA (Value Not Available)
 indicates that this value was not measured. Abdomen length (mm) - The
 length of the abdomen from its anterior junction with the thorax to its
 posterior end, in mm. VNA (Value Not Available) indicates that this value
 was not measured. Body length (mm) - Distance from the tip of the head to
 the tip of the abdomen, in mm. VNA (Value Not Available) indicates that
 this value was not measured. ## Code/Software Excel was used to enter the
 data and R was used to clean and analyze the data and produce visual
 graphics. Packages in R used: bipartite - to analyze network data dplyr
 tidyverse SpadeR MuMin vegan ggplot2 nlme MASS lme4 lmerTest ## Version
 Changes **30-april-2025:** Corrected the spelling of three Dipteran
 species' names in the #Interaction Data 2019 Excel spreadsheet tab.