Avaluació dels efectes de la vespa asiàtica (Vespa velutina) en la biodiversitat

Abstract

Biological invasions represent a significant contributor to global biodiversity loss. Their high dispersal capacity, competitiveness, and lack of predators have enabled them to displace and exterminate numerous native species. This study focuses on the yellow-legged hornet (Vespa velutina), an invasive species that has become established in Europe in recent decades. Among the effects described, the impact on honeybees stands out, as it hinders the survival of colonies in bee farms. Conversely, the effects on biodiversity are not as clear. In light of this, the present study aims to deepen our understanding of these effects by focusing on two lines of research. On the one hand, the behaviour of this species was studied in ivy (Hedera helix) populations, as flowering coincides with the peak activity of the yellow-legged hornet. This was achieved by several recounts of the individuals present in the populations and by recording the behaviour of the yellow-legged hornet in order to identify potential capture preferences and to provide a detailed account of the behaviour observed in these populations. On the other hand, the influx of the invasive species in different plant species was compared in order to identify potential preferences in resource searching. Finally, a bibliographical review of the impacts described to date, has compiled the current state of knowledge on the subject, thus facilitating its dissemination to local administrations. In relation to the results obtained on ivy populations, a positive relationship with the Calliphoridae family was demonstrated, which significantly describes the abundance of the invasive taxon. Furthermore, behavioural analysis showed that hunting is the main activity exerted by the hornet in ivy populations, although the recorded capture success is low. In terms of plant species selection, only Fatsia japonica and Eriobotrya japonica were visited by the yellow-legged hornet, indicating a clear preference over other species. Finally, the literature review revealed a more comprehensive understanding of the impacts on honey bees compared to the other impacts. While several studies have addressed the impact on biodiversity, the results remain inconclusive