Multiple introductions and overwintering shape the progressive invasion of Aedes albopictus beyond the Alps

Abstract

Aedes albopictus originates from Southeast Asia and is considered one of the most invasive species globally. This mosquito is a nuisance and a disease vector of significant public health relevance. In Europe, Ae. albopictus is firmly established and widespread south of the Alps, a mountain range that forms a formidable biogeographic barrier to many organisms. Recent reports of Ae. albopictus north of the Alps raise questions of (1) the origins of its recent invasion, and (2) if this mosquito has established overwintering populations north of the Alps. To answer these questions, we analyzed population genomic data from >4000 genome‐wide SNPs obtained through double‐digest restriction site‐associated DNA sequencing. We collected SNP data from specimens from six sites in Switzerland, north and south of the Alps, and analyzed them together with specimens from other 33 European sites, five from the Americas, and five from its Asian native range. At a global level, we detected four genetic clusters with specimens from Indonesia, Brazil, and Japan as the most differentiated, whereas specimens from Europe, Hong Kong, and USA largely overlapped. Across the Alps, we detected a weak genetic structure and high levels of genetic admixture, supporting a scenario of rapid and human‐aided dispersal along transportation routes. While the genetic pattern suggests frequent re‐introductions into Switzerland from Italian sources, the recovery of a pair of full siblings in two consecutive years in Strasbourg, France, suggests the presence of an overwintering population north of the Alps. The suggestion of overwintering populations of Ae. albopictus north of the Alps and the expansion patterns identified points to an increased risk of further northward expansion and the need for increased surveillance of mosquito populations in Northern Europe.

Predicting the time of arrival of the Tiger mosquito (Aedes albopictus) to new countries based on trade patterns of tyres and plants

“…However, climatic restrictions to the introduction and establishment of the species are likely to decrease in future, as climate change is expected to expand the areas having suitable conditions and facilitate the species dispersal in different parts of the world (Kamal et al, 2018; Khan et al, 2020; Kraemer, Golding, et al, 2019; Kraemer, Reiner, et al, 2019; Oliveira et al, 2021). Additionally, Aedes albopictus has shown the ability to adapt locally to lower temperatures with overwintering via egg diapause, as found in the USA (Medley et al, 2019), in Germany (Kuhlisch et al, 2018) and even crossing north of the Alps in Europe, considered hitherto the main obstacle to the local dispersion of the mosquito (Vavassori et al, 2022), revealing an increased capability of the species to expand to areas with colder climate.…”

“…Another recent study based on genomics was done for Australia, having traced incursions of Aedes albopictus along marine routes with origins in China, Japan, Singapore and Taiwan (Schmidt et al, 2020). Indeed, the pathways of dispersal of the Aedes albopictus mosquito have been mostly identified by genomic population data from countries where the species is present (Swan et al, 2022; Vavassori et al, 2022), confirming the importance of international trade from genetic markers of existing groups.…”

The increasing threat of Rift Valley fever virus globalization: strategic guidance for protection and preparation

“…Also, landscapes may become more permissive to RVFV thriving from more (or less) stability of local meteorology which could create increasing year-round suitability for vectors, as well as dissolving barriers to expansion of vector, virus, and vertebrate host populations and thus increased connectivity regardless of changes in local human activities. Warming climate in northern countries expands north and to higher elevations the year-round habitable zone for mosquito populations (Vavassori et al 2022), which could translate to increased spatial and temporal opportunity for import of RVFV when endemic activity is historically high—i.e., in the historically winter months of November–February in northern countries. Globally, from a first principles perspective, regions or areas which offer opportunities for RVFV establishment are those that are ENSO-teleconnected similar to regions in Africa: they respond similarly to either El Niño or La Niña (Fig.…”

Population‐specific responses to developmental temperature in the arboviral vector Aedes albopictus: Implications for climate change

“…The Asian tiger mosquito Aedes albopictus is a highly invasive mosquito of prime public‐health relevance due to its vector competence for arboviruses such as dengue, Zika and chikungunya (Bonizzoni et al., 2013; Manni et al., 2017; Pichler et al., 2019; Vavassori et al., 2022). In the past 50 years, this species has conquered every continent, except Antarctica, from its native home range in Asia and from islands of the Indian Ocean and the Pacific, which it had colonized during the spice trade (17th–18th century) (Delatte et al., 2011; Ducheyne et al., 2018).…”