The Directorate General of Public Health of the Government of the Canary Islands has reported the presence of larvae and adult specimens of the invasive mosquito Aedes albopictus, known as the tiger mosquito, on a farm located in the ravine mouth area of the municipality of Valle Gran Rey, on the island of La Gomera. This marks the first detection of this invasive species on the island.
The alert originated last week following a citizen notification received through the institutional email address designated for entomological surveillance in the Canary Islands. Personnel from the University Institute of Tropical Diseases and Public Health of the Canary Islands (IUETSPC) of the University of La Laguna inspected the farm and collected specimens that were subsequently identified as Aedes albopictus.
Following the discovery, the Entomological Surveillance System of the Canary Islands has been activated. Traps have been deployed, the area has been inspected, and residents of the area are being informed to alert them about the presence of these mosquitoes. It is believed to be an accidental and isolated introduction of the vector.
The agreed-upon actions were determined during a meeting of the Canary Islands Autonomous Entomological Surveillance Committee, involving representatives from the Cabildo of La Gomera, the Ayuntamiento of Valle Gran Rey, and the Directorate General of Public Health. These actions will include inspection, elimination of potential breeding sites, and the placement of more traps to ascertain the extent of the mosquito's presence.
The Ayuntamiento of Valle Gran Rey will carry out fumigation and cleaning operations in the area. Institutions, companies, and residents will be informed about the necessary actions, and recommendations will be provided to prevent proliferation, as citizen collaboration is essential.
The Aedes albopictus is a black mosquito with stripes, smaller than those typically found in our region, which adapts to breeding in small water accumulations created by humans. While it is a vector for viral diseases in other geographical areas, these pathologies are not endemic in the Canary Islands. It usually bites during the day, particularly at dawn and dusk, and its bite causes a strong inflammatory reaction.
Health authorities emphasize the importance of citizen collaboration in identifying potential invasive mosquitoes and eliminating their breeding sites. Suspected sightings can be reported with photographs to vectores.scs@gobiernodecanarias.org, including the location and a contact phone number. Surveillance enables early detection of larvae and eggs.
It is important to note that bites have only been reported at the alerting farm, and the mosquito's presence does not imply the transmission of diseases such as dengue or zika in the Canary Islands, except for sporadic imported cases.
Preventive measures include controlling and eliminating any water accumulation, such as in plant pot saucers, vases, outdoor containers, puddles, appliance drip trays, and drains. Swimming pools should be kept well-chlorinated and with daily circulation.
The Canary Islands have had an Entomological Surveillance Service at Ports and Airports since 2013 to prevent the entry of invasive mosquitoes. The system monitors entry points, activates bite surveillance programs, and analyzes cases reported by citizens.
Since the service's launch in 2019, eradication of other species' episodes has been declared in Fuerteventura, La Palma, and Tenerife. Episodes of Aedes albopictus detection are ongoing at Tenerife South Airport and in Tuineje (Fuerteventura), and of Aedes aegypti at the port of Santa Cruz de Tenerife and in Las Palmas de Gran Canaria.
