• Citizen collaboration is key to preventing their proliferation, eliminating possible breeding sites and avoiding accumulations of water.
• In 2025, 68 areas in 46 municipalities are being sampled: 9 in Araba, 20 in Bizkaia and 17 in Gipuzkoa. Monitoring began in the first week of June and will continue until the beginning of November.
• The control of this invasive species is carried out through sampling, detecting it in 70 municipalities since the surveillance programme was launched in 2013.

 

The Basque Government’s Department of Health, together with the Basque Institute for Agricultural Research and Development NEIKER and Basque town councils, are once again calling for prevention to stop the spread of the tiger mosquito.

 

Since 2013, this species has been controlled in the Basque Country within the framework of the Tiger Mosquito Detection Surveillance Programme led by the Department of Health, together with NEIKER and Basque town councils, which has enabled its presence to be identified in 70 Basque municipalities, especially in the most densely populated areas and largest cities in Bizkaia and Gipuzkoa. Monitoring is carried out through sampling based on the placement of traps in urban and peri-urban areas that attract female mosquitoes where they lay their eggs. The analysis of these samples makes it possible to monitor the presence and distribution of this species.

 

In 2025, the surveillance plan covers a total of 68 sampling areas in 46 municipalities: 9 in Araba, 20 in Bizkaia and 17 in Gipuzkoa. Surveillance began in the first week of June and will last until the week from 3 to 7 November 2025, encompassing the period of greatest tiger mosquito activity.

 

Recommendations to citizens

Citizen collaboration, together with the work of municipal services, is key to stopping the spread of the tiger mosquito, mainly by adopting measures to prevent its reproduction. Mosquitoes need small amounts of water to lay their eggs, so the most effective way is to eliminate possible breeding sites, avoiding accumulations of water in our homes and urban areas.

 

In this sense, it is recommended to:

• Avoid accumulations of water in drainage areas (gutters and sewers) and roof gutters.
• Plug up any holes in private and public land where water is continuously retained.
• Empty containers that accumulate water twice a week: dishes under flower pots, vases, buckets, toys, plastic pools, etc.
• Renew the water in our animals’ drinking troughs every 2 or 3 days. Pour water down drains at least once a week to avoid stagnation.
• The use of mosquito nets on windows, tanks, containers, etc. can prevent mosquitoes from entering and laying eggs.

 

This year, special emphasis has also been placed on urban areas with a higher probability of breeding sites, such as orchards and cemeteries, where there may be more accumulations of water, reinforcing prevention with specific posters in these environments.

 

Citizens can cooperate with the identification of the tiger mosquito through the Mosquito Alert application. It is a citizen science platform that allows us to discover the presence of the mosquito in places where it was not known to be present, update its distribution or improve monitoring. It is a matter of geolocating the mosquito, taking a good photo and sending it to the application: https://www.mosquitoalert.com

 

What to do if you get a tiger mosquito bite

 

This small black mosquito (around 5 mm in size), recognisable by its white line on the head and thorax, is diurnal, so it usually bites during the day, unlike native mosquitoes, which usually bite at night. Moreover, it is common for them to bite several times in a row. Tiger mosquito bites can be more painful and cause an intense reaction, so it is recommended to clean the area with soap and water and apply cold to reduce inflammation and attenuate itching. In addition, do not scratch to prevent the area from becoming infected. If the reaction is very intense and causes discomfort or even breathing difficulties, health care personnel should be consulted.

 

A person who has travelled to an area at risk should, for 15 days after their return, take extreme personal protective measures to avoid mosquito bites. If, in addition, symptoms (mainly fever, signs of pain, discomfort, etc.) begin to appear, they should consult their health centre as soon as possible. This invasive species is capable of transmitting diseases such as dengue, zika and chikungunya, although the probability of infection in the Basque Country is very low, as no local cases have been detected.