Emerging Risk of Cross-Species Transmission of Honey Bee Viruses in the Presence of Invasive Vespid Species

Simple Summary Currently, bee viruses are one of the threats to honey bee populations. The increase in invasive Vespid species causes a negative impact on honey bee colonies, weakening them and making them more vulnerable to the presence of pathogens. This bibliographic review shows the main research on bee viruses in the Vespa, Vespula and Polistes genera belonging to the Vespidae family. This taxon contains several of the most widespread invasive Vespid species worldwide. Many of these species are predators of honey bees and cause great impacts, as is the case with the yellow-legged hornet Vespa velutina. The presence of viruses in species of Vespids that interact with honey bees could represent an emerging risk in the transmission of pathogens, weakening the defense strategies of native species. Gathering this information is necessary to promote the research on the spread of bee viruses associated with invasive species as well as in the development of bee virus control strategies. The increase in invasive alien species is a concern for the environment. The establishment of some of these species may be changing the balance between pathogenicity and host factors, which could alter the defense strategies of native host species. Vespid species are among the most successful invasive animals, such as the genera Vespa, Vespula and Polistes. Bee viruses have been extensively studied as an important cause of honey bee population losses. However, knowledge about the transmission of honey bee viruses in Vespids is a relevant and under-researched aspect. The role of some mites such as Varroa in the transmission of honey bee viruses is clearer than in the case of Vespidae. This type of transmission by vectors has not yet been clarified in Vespidae, with interspecific relationships being the main hypotheses accepted for the transmission of bee viruses. A majority of studies describe the presence of viruses or their replicability, but aspects such as the symptomatology in Vespids or the ability to infect other hosts from Vespids are scarcely discussed. Highlighting the case of Vespa velutina as an invader, which is causing huge losses in European beekeeping, is of special interest. The pressure caused by V. velutina leads to weakened hives that become susceptible to pathogens. Gathering this information is necessary to promote further research on the spread of bee viruses in ecosystems invaded by invasive species of Vespids, as well as to prevent the decline of bee populations due to bee viruses.