The Japanese mosquito, a carrier of pathogenic viruses, has arrived in Navarre

Japanese mosquito (Aedes Japonicus) is a species native to Japan and Korea, discovered in Europe (Normandy, France) in 2000. It was first noticed in Spain in the city of Siero (Asturias) in 2018. This September Enrique Bakero, Researcher, Institute of Biodiversity and Environment BIOMA, University of Navarra, identified a specimen inside a building in Pamplona in broad daylight.

“The advance of this mosquito is slow but continuous in the east of Spain, and so far, in addition to Asturias, it has already been seen in Cantabria and Guipuzcoa. And its spread, as with other invasive mosquito species, is driven primarily by the movement of people and goods,” he says.

According to published studies consulted by the expert, the Japanese mosquito is more resistant than other species to the winter temperatures found in temperate regions, and the eggs are resistant to freezing and desiccation, remaining inactive during the winter. In addition, Enrique Baquero assures, this type of mosquito is more resistant to pollution in breeding areas, so it can potentially spread at a faster rate. “In temperate regions such as Navarre, adults will be present from early summer and will remain active until early autumn.”

WEST NILE VIRUS, DEHE AND CHIKUNGUNYA

Vector competition in the transmission of West Nile virus (WNV), dengue, and chikungunya viruses has been demonstrated in this mosquito species. The potential for transmission of these arboviruses—viruses that infect vertebrates—has raised concerns that this could become a public health problem, especially because they readily colonize urban environments with high population densities.

“In Navarra we have a large number of birds of prey and we are also in a bird migration funnel, which increases the possibility of WNV transmission as the presence of this new vector is added to an already existing species. That Culex pipiens

which is currently the common carrier of this virus,” adds Enrique.

A recent scientific review (Petersen et al., 2024) assessing the potential risks of mosquitoes to human health identified these mosquitoes as among the most monitored species and stated that they pose a significant risk for the transmission of new viruses. . Baquero emphasizes the importance of studying zoonoses—diseases transmitted from animals to humans—and analyzing interactions between human populations and animal communities.

“BIOMA Institute researchers are always on the lookout for our biodiversity research, monitoring the emergence of new animal species in order to identify them and evaluate scientifically the implications they may have for human health (One Health) and the importance of ecological balance,” he concludes.