Buzzworthy invasions: new data on alien Vespa (Hymenoptera, Vespidae) hornets in southern Spain

Abstract The genus Vespa , commonly known as hornets, comprises eusocial wasps capable of forming large colonies. It includes 22 recognized species, mostly native to Asia and Oceania. Some of them are considered invasive species due to their introductions outside their native ranges and the impacts they can have on biodiversity and human health. Until now, four non-native Vespa species have been documented in the Iberian Peninsula. This study provides an updated distribution of the Oriental hornet ( Vespa orientalis ) and the Black shield hornet ( Vespa bicolor ) in southern Spain (Iberian Peninsula), offers insights into their ecology in their new territories, and documents the southernmost European nest of the Asian hornet ( Vespa velutina ) in its invasive range. We used data from citizen science platforms, literature and field observations to map the spread of these species over several years. V. orientalis and V. bicolor have expanded their respective distributions and exhibit a notable affinity for urban and peri-urban coastal environments, and both species have shown scavenging and preying behavior on several native species and visiting both wild and exotic ornamental plants. However, we have located specimens inside national parks that may constitute a new threat to native fauna. Recent records of V. velutina in Cádiz and Huelva provinces suggest ongoing southward expansion. Our findings support the role of urban areas as primary habitats and potential hubs for the spread of these introduced species, raising concerns about impacts on native ecosystems and human activities. These results underscore the need for continued monitoring and ecological studies to better understand the invasion dynamics and ecological implications of these hornet species on the Iberian Peninsula and Europe, where citizen science platforms could be a useful tool (after accounting for their limitations and bias) to help to trace the expansion of these hornets.