First record of Aedes japonicus in Liguria region, Northwest of Italy

Aedes japonicus is an invasive Asian mosquito species, and to date it is widespread in many European countries. In Italy, it was first recorded in 2015 at the Austrian border and it then spread throughout the Northeast of the country. In 2019, it was also identified in Piedmont region, near the Swiss border. In the framework of the Italian program for prevention, surveillance, and response to Arboviruses, from June to November 2021, biweekly entomological surveillance was performed in the Liguria region (Northwest Italy). The collected mosquitoes were morphologically and genetically identified and molecularly analysed for the detection of West Nile and Usutu viruses. Six female mosquitoes, trapped on the 6th of July 2021 using a gravid trap in Albenga (Savona province), were morphologically identified as Ae. japonicus and the identification was genetically confirmed. The pool tested was negative for the presence of West Nile and Usutu viruses. The detection of Ae. japonicus was performed in a coastal area characterized by the presence of many floriculture activities. Considering the distance from the established Ae. japonicus mosquito populations in Italy and other European countries, this could represent an independent introduction in this country.