DOI: 10.5061/dryad.f4qrfj783
title: Internet images reveal bumblebee-mimicking hoverflies follow models in preferring blue flowers, but retain the typical hoverfly attraction to yellow

description: Batesian mimics, such as hoverflies, resemble noxious species that
 predators avoid, such as bees. Such resemblance can be behavioural as well
 as morphological. Unlike other Hymenopterans, eusocial bees commonly
 prefer blue flowers. In contrast, flies generally prefer yellow and white.
 We predicted that hoverflies mimicking eusocial bees would prefer blue
 rather than yellow flowers, following their models. We gathered internet
 photographs of flower-visiting bees and wasps, their hoverfly mimics, and
 non-mimetic hoverflies, and compared the colours of the visited flowers.
 Flowers visited by bumblebees were "bluer" than those visited by
 other hymenopterans (honeybees, social wasps, and solitary bees).
 Correspondingly, flowers visited by bumblebee-mimicking hoverflies were
 bluer than those visited by non-mimics, and as blue as those visited by
 bumblebees. There was no such pattern in flower "yellowness",
 where all flies and most hymenopterans preferred similar yellowness, and
 only bumblebees chose less-yellow flowers than others. Our study
 demonstrates changes in microhabitat choice associated with Batesian
 mimicry across a diverse clade of flies. Our findings suggest selection
 for behavioural mimicry, or that common microhabitats select for
 morphological mimicry. Mildly noxious models such as bumblebees exert
 particularly strong selection for mimetic accuracy, suggesting that
 habitat-choice mimicry may be selected to enhance morphological mimicry.
description: # Internet images reveal bumblebee-mimicking hoverflies follow models in
 preferring blue flowers, but retain the typical hoverfly attraction to
 yellow. ## Short summary of the study We gathered internet photographs of
 flower-visiting bees and wasps, their hoverfly mimics, and non-mimicking
 hoverflies, and compared the colours of the visited flowers. We predicted
 that, driven by selection for enhanced mimicry, bee-mimicking hoverflies
 would have switched flower preference from yellow to blue, to follow the
 flower choices of their models. ## Files included ###
 Syrphid_behavioural_mimicry_-_results_and_code.Rmd R Markdown file that
 reproduces the results section of the paper from the files enclosed here.
 Some figures are produced in R but compiled manually - this is indicated
 in the code comments. ### Table_S1_model-mimic_ids.xls Table of mimics and
 corresponding models compiled from literature (modified from Gilbert, F.
 2025 (in press). The Biology of the Hoverflies (Diptera, Syrphidae).
 London, England: CABI and Royal Entomological Society). NB. References are
 given in the separate worksheet. This file is not used in the code, so
 there is no corresponding .csv file (see Table S4 species pairs.csv)
 Hoverfly species: The species in question (divided into bumblebee mimics,
 honeybee mimics, solitary bee mimics, social wasp mimics and non-mimics)
 Model genera: Genera of models identified in the literature (see
 references). Species identified: species of models identified in the
 literature (see references). ### Table_S2_head_width.xlsx ###
 Table_S2_head_width.csv Table of head widths for syrphids in
 dataset. These data are a combination of direct measurement and
 interpolation based on other traits (see text for details). species:
 Species of Syrphid head width (mm): Head width in mm Interpolated or
 measured: Whether interpolated or measured (see text for details) ###
 Table_S3_main_data.xlsx ### Table_S3_main_data.csv Main data table - data
 on morphotype group (see text for details), model species (for mimics),
 and median RGB flower colour for each photograph. Metadata are contained
 in a separate worksheet in the .xlsx file and are replicated here:
 species: Species name of mimic or model group: morphotype group (see text
 for details): bbee = bumblebee; hbee = honeybee; sbee = solitary bee;
 swasp = social wasp; mim = mimic; non = non-mimic; mod = model
 pair_species Model species (see text and Table S1 for details). Note that
 non-mimics are coded NA here because they are not mimics and do not have a
 model. pair2: Model search string; for use in grouping model-mimic pairs
 (see code for details) r: Median red content of flower cutout (0-255) g:
 Median green content of flower cutout (0-255) b: Median blue content of
 flower cutout (0-255) ### Table_S4_species_pairs.xlsx ###
 Table_S4_species_pairs.csv Table of species pairs connecting models to
 mimics and vice versa. group: morphotype group (see text for details):
 bbee = bumblebee; hbee = honeybee; sbee = solitary bee; swasp = social
 wasp; mim = mimic; non = non-mimic; mod = model pair2: Model search
 string; for use in grouping model-mimic pairs (see code for details)
 pair_id: Model-mimic pair ID ### Supplementary_file_S4_-_phylogeny.nex
 Syrphid phylogeny at the genus level in NEXUS format. For analysis,
 species in the dataset are added in to this at the coding stage (see code
 for details).