138 | Genetic studies to investigate the taxonomic issues of Vespa velutina and Vespa orientalis, expanding in Italian urban and agricultural areas

Valeria Maselli¹, Mariangela Norcia¹, Alessia Illiano², Paolo Bonivento³ | ¹Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Napoli, Italy; ²NEW ECO srl, Trieste, Italy; ³Istituto di Studi Europei “A. De Gasperi”, Roma, Italy.

The accelerating spread of invasive alien species (IAS) represents a critical challenge for biodiversity conservation, agricultural stability, and public health across Europe. In Italy, increasing concern has focused on the expansion of two hornet species: Vespa velutina (the Asian yellow-legged hornet) and Vespa orientalis (the Oriental hornet). While V. velutina is an accidentally introduced invasive species that primarily preys on honeybees, the status of V. orientalis is more complex: it has historically been present in Southern Italy but has recently expanded aggressively northward into urban centers, including Trieste. This presentation outlines a comprehensive genetic study aimed at resolving persistent taxonomic uncertainties and tracing the invasion pathways of these hymenopterans within the Italian peninsula. Accurate taxonomic identification is the cornerstone of effective pest management; accordingly, the primary objective of this research is to apply molecular markers to clarify the population structure and genetic diversity of Italian populations of both species. Moreover, we investigate novel molecular markers that can discriminate among V. velutina, V. orientalis, and the native V. crabro (the European hornet), facilitating accurate identification in both ecological studies and applied management frameworks. By employing mitochondrial DNA (mtDNA) sequencing, we aim to provide robust genetic signatures for specimens collected along an urban–agricultural gradient. This phylogeographic approach allows the reconstruction of invasion trajectories, the estimation of the number of introduction events, and the assessment of potential genetic bottlenecks. Furthermore, this research examines the critical intersection between these species and anthropogenic environments. Both invasive hornets exhibit synanthropic behavior, nesting in human-made structures and exploiting urban food waste, thereby significantly increasing the risk of dangerous human–insect interactions. By integrating genetic data with information on nesting sites (urban vs agricultural), we can assess whether specific genotypes are associated with higher levels of synanthropy or aggression. The integration of genetic data with ecological monitoring is proposed as a standardized framework for managing the ongoing expansion of these ecologically and socioeconomically important hymenopterans.