Internet images reveal bumblebee-mimicking hoverflies follow models in preferring blue flowers, but retain the typical hoverfly attraction to yellow

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 bumblebee..., , # 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, Syrp...,