Aedes (Stegomyia) aegypti in ditches from an arid region of Argentina

• New Aedes aegypti breeding sites in an arid region of Argentina.

• Artificial irrigation systems are breeding sites for Aedes aegypti in arid areas.

• Despite the unfavorable site conditions, this mosquito is able to develop.

Aedes aegypti is the primary vector of dengue worldwide and is able to transmit several other arboviruses of public health importance. Despite extensive research on its ecology throughout the world, limited attention has been given to arid regions. The province of San Juan is an arid region of Argentina with unique climatic characteristics commonly known as the “monte ecoregion”. It has scarce precipitation and, therefore, has a network of irrigation canals that supply water to the region. The canal system is outdated, poorly maintained and, accumulating small bodies of water of anthropic origin. Urban ditches were checked from January to December 2019, and during January to June, 771 immature specimens of A. aegypti were found. In this work, we report the presence of A. aegypti in ditches, describing for the first-time new breeding sites that, despite their extreme physical and chemical properties, were used as successful larval habitats. The remarkable adaptability of A. aegypti in this breeding sites raises concerns about the possible detection and spread of dengue cases in the province. The alarming expansion of dengue cases in the region further highlights the urgent need to take control measures against this insect.