The invasive Aedes albopictus in the Doñana World Heritage Site.

Background: Aedes albopictus is catalogued as one of the 100 most dangerous species worldwide. Native to Asia, the species has drastically increased its distribution range, reaching all continents except Antarctica. The presence of Ae. albopictus in Spain was first reported in 2004 in Cataluña (NE Spain), and it is spreading in the country.

Methods: We conducted an extensive mosquito monitoring study in the natural protected area of the Doñana National Park (SW Spain) in 2023. After identifying the presence of Ae. albopictus, a mosquito control strategy was developed and implemented to eradicate the species in the area.

Results: Overall, 12,652 mosquito females of 14 different species were captured at nine sites within the park. For the first time, the presence of Ae. albopictus was recorded in the area, despite intensive trapping performed at some localities since 2003. The presence of this invasive species in the park is most likely linked to human activities, potentially facilitated by daily car trips of personnel. Although larvae of Culex, Anopheles, and Culiseta mosquitoes were identified in these containers, the presence of Ae. albopictus larvae was not recorded in those locations. In spite of that, the biological larvicide Bacillus thuringiensis israelensis (Bti) was applied to artificial containers potentially used by Ae. albopictus as breeding sites.

Conclusions: This work evidences the high capacity of Ae. albopictus to reach highly conserved natural areas far from urban foci. We discuss the implications of the presence of Ae. albopictus in this endangered ecosystem and the potential control measures necessary to prevent its reintroduction.