Abstract
The Asian giant hornet, Vespa mandarinia, is an invasive species that could potentially destroy the local honeybee industry in North America. It has been observed to nest in the coastal regions of British Columbia in Canada and Washington State in the USA. What is the source population of the immigrant hornets? The identification of the source population can shed light not only on the route of immigration but also on the similarity between the native habitat and the potential new habitat in the Pacific Northwest. We analyzed mitochondrial COX1 sequences of specimens sampled from multiple populations in China, the Republic of Korea, Japan, and the Russian Far East. V. mandarinia exhibits phylogeographic patterns, forming monophyletic clades for 16 specimens from China, six specimens from the Republic of Korea, and two specimens from Japan. The two mitochondrial COX1 sequences from Nanaimo, British Columbia, are identical to the two sequences from Japan. The COX1 sequence from Blaine, Washington State, clustered with those from the Republic of Korea and is identical to one sequence from the Republic of Korea. Our geophylogeny, which allows visualization of genetic variation over time and space, provides evolutionary insights on the evolution and speciation of three closely related vespine species (V. tropica, V. soror, and V. mandarinia), with the speciation events associated with the expansion of the distribution to the north.