Shedding light on overlooked pollinators: Global insights into floral interactions of velvet ants (Hymenoptera: Mutillidae and Myrmosidae)

Plant-animal interactions constitute a recurrent and central focus in ecological research, with pollination representing one of its most extensively studied aspects. While certain insect orders have traditionally received considerable attention due to their abundance as flower visitors and their efficiency in pollination, it is undeniable that the significance of other less popular and neglected flower visitors cannot be overlooked. In this regard, velvet ants (Hymenoptera: Mutillidae and Myrmosidae) constitute an excellent study model, as the knowledge of their ecology (e.g., their feeding preferences) is still very limited despite being reported as common flower visitors. In this study, we conducted a comprehensive global review of velvet ant floral visitation patterns using citizen science data, literature records and unpublished data. We used network metrics to explore their flower-visit preferences on a global scale, as well as depending on the bioregion where the interaction was recorded and the sex of the velvet ants. In addition, we explored their potential role as pollen vectors examining the number of photographic records where velvet ants had pollen attached to their bodies. Our analyses revealed that velvet ants are generalist flower visitors of a wide range of plant families, with Apiaceae, Asteraceae, Euphorbiaceae, Rhamnaceae and Fabaceae as the most visited. Despite differences in flowering plant and velvet ant composition across bioregions causing differences in plant-velvet ant interactions, velvet ants visited flowering plants in a generalistic way across the globe. Males and females seemed to visit different plant communities, with males being more generalist than females. Furthermore, 42.7% (likely an underestimation) of the photographic records of velvet ants visiting flowers showed pollen attached to their bodies in the same way as in other pollinating insects, suggesting the same potential role as pollinators. There remains ample scope for ongoing investigation to comprehensively assess the importance of numerous arthropods, including velvet ants, not only as flower visitors but also as potential pollinators.