[en] The increasing spread of Aedes (Stegomyia) albopictus (Skuse, 1894)—commonly known as the Asian tiger mosquito and potential vector of various arboviruses —along the Spanish Mediterranean coast and the intense traffic between this area and the Community of Madrid had increased the risk of its arrival in the latter region. Thus, in 2016 the Community of Madrid's Health Department set up a program for the entomological surveillance and environmental health control of vectors that transmit arboviruses (dengue, chikungunya and zika).The aim of this paper is to analyze the information obtained in the course of this program from 2016 till 2020. Entomological surveillance was designed along the big axes formed by the radial highways that link Madrid with the Mediterranean coast. This active surveillance consisted in installing lethal ovitraps and looking for larvae hatcheries. This was complemented with passive, citizen-based surveillance via channels such as Mosquito Alert. In the summer of 2017, eggs resembling those of Ae. albopictus were found in a trap installed at a gas station on the N-III Highway. In 2018, two persons respectively submitted photos of adult mosquitoes they had seen in two municipalities of the Community of Madrid—Velilla de San Antonio and Rivas- Vaciamadrid, which were later confirmed to belong to this species by the Entomology Laboratory of the Complutense University of Madrid's Biological Sciences Faculty. Subsequent entomological surveillance in these two municipalities showed that the Asian tiger mosquito had already settled in the former but not in latter. However, a second reintroduction apparently occurred in 2020, the presence of this species being confirmed in Rivas-Vaciamadrid.

[es] La creciente implantación de Aedes (Stegomyia) albopictus (Skuse, 1894), vector potencial de varias arbovirosis, comúnmente conocido como mosquito tigre, en el litoral mediterráneo y el gran tráfico existente entre esos lugares y la Comunidad de Madrid, aumentaba el riesgo de su llegada a la región. Por ello, esta Comunidad estableció, en el año 2016, el Programa de Vigilancia Entomológica y Control Sanitario-Ambiental de Vectores Transmisores de Arbovirus (dengue, chikungunya y zika). El objetivo de este manuscrito es analizar la información obtenida desde su puesta en marcha en 2016 hasta 2020. La vigilancia entomológica se diseñó en torno a los grandes ejes de las carreteras que comunican Madrid con el Mediterráneo. Esta vigilancia activa se realiza mediante la colocación de trampas de oviposición, de adultos y la prospección de criaderos larvarios. Se complementa mediante vigilancia pasiva con dispositivos como Mosquito Alert. En verano del 2017 se detectó la presencia de huevos compatibles con Ae. albopictus en una trampa ubicada en una gasolinera de la Nacional III. En el 2018, dos ciudadanos remitieron sendas fotos de mosquitos adultos encontrados en dos municipios de la Comunidad de Madrid, Velilla de San Antonio y Rivas-Vaciamadrid, que fueron confirmados por el laboratorio de entomología de la Facultad de Ciencias Biológicas (Universidad Complutense de Madrid), como Ae. albopictus. El seguimiento entomológico posterior en estos dos municipios refleja el establecimiento del mosquito tigre en el primer municipio que no se confirmó en Rivas en 2018, pero sí en 2020 cuando aparentemente se produjo una segunda reintroducción.