Population Structure of the Invasive Asian Tiger Mosquito, Aedes albopictus, in the Americas

The Asian tiger mosquito (Aedes albopictus) is an invasive species that has become widespread throughout the Americas. It is a vector for several arboviruses, making it an increasing threat to human health as its range expands. To characterize population genetic structure and gain insight into the origin and spread of this invasive mosquito, we genotyped 959 individuals using ~20k SNPs. We included 50 localities across the Americas, and previously genotyped mosquitoes from 28 localities in Asia and 14 in Europe. Our analyses revealed that populations in North America were distinct from populations in South America, and this relationship was consistently supported across analyses. Most North American mosquitoes shared a common origin with those from Japan and Southern Europe (e.g., Italy, Spain), with the exception of individuals from California, which clustered with more southern areas of East Asia (China and Vietnam), as well as Greece. Brazilian and Argentinian populations were distinct from all other sampled locations, including those in the native range, but were most closely related to mosquitoes from more tropical locations in South and Southeast Asia. By revealing the likely sources of invasions in the Americas, our findings have important implications for understanding invasion dynamics of this species.