Giants in America: Population genomics of the invasive hornet Vespa mandarinia

The Northern Giant Hornet Vespa mandarinia could be a major threat to populations of the Western honey bee Apis mellifera, which lack defences against this destructive predator. V. mandarinia was first detected in North America in 2019, and now appears to be becoming established in Washington, USA and British Columbia, Canada. Though they have not yet eradicated V. mandarinia in North America, efforts to identify and destroy invasive nests have generated a wealth of samples, which can now be sequenced to track the origins, spread and diversity of this invasive population.

Here, we present whole-genome population genomic data from invasive V. mandarinia in North America. Using these data, together with newly-sequenced data from the hornet’s native range in South-East Asia, we identify routes by which this highly invasive predator has likely spread to its newly-established invasive range. In addition, we attempt to identify the degree of genetic diversity present in the invasive population, in particular at the sex determination locus. Since heterozygosity at this locus is required for the production of workers and gynes in social hymenopterans, lack of genetic diversity could be a major limiting factor for the invasive potential of V. mandarinia in North America.