19 May 2025 Press releases

The mosquito season has begun

The tiger mosquito is spreading in Belgium, citizens at the heart of surveillance.

With the arrival of the mosquito season in Belgium, the Institute of Tropical Medicine (ITM) and Sciensano are again calling on citizens to remain vigilant and to report the fast-spreading tiger mosquito (Aedes albopictus) via the citizen science platform MosquitoSurveillance.be. In 2024, tiger mosquitoes were reported in 21 municipalities, 11 of them for the first time.

The tiger mosquito is gaining ground

In 2024, citizens reported 47 tiger mosquitoes via MosquitoSurveillance.be, across 21 municipalities in Belgium. In Flanders, the tiger mosquito was reported in six municipalities for the first time (Berchem, Boom, Gent, Humbeek, Vilvoorde and Wijnegem,) and in nine where it had already been detected in previous years (Evergem, Hoegaarden, Kessel-Lo, Leuven, Melle, Puurs-Sint-Amands, Schelle Wilrijk and Wolfsdonk). In Wallonia, there were sightings in two new municipalities (Baudour and Verviers) and one known municipality (Ath). In Brussels, reports came from three new municipalities: City of Brussels, Forest and Sint-Joost-ten-Node.

This year, field inspections confirmed overwintering in Ath, Kessel-Lo and Puurs-Sint-Amands. Including Wilrijk and Lebbeke, where overwintering was confirmed in 2023, it brings the total number of locations where the tiger mosquito is becoming established in Belgium to five.

Tiger mosquito

The tiger mosquito (Aedes albopictus) is an invasive species that reached Europe through the importation of used car tyres and lucky bamboo. It was able to spread further by hitching rides in cars and other means of transport from regions where it is already established.
The tiger mosquito is black with white stripes. It has a white stripe on the back of its back, five white stripes on its legs and white at the tips of its hind legs.
It can transmit viruses like dengue, chikungunya and Zika viruses.

The Asian tiger mosquito (Aedes albopictus)

"In 2024, we’ve seen multiple reports of tiger mosquitoes along the A12 between Brussels and Antwerp,” says Wim Van Bortel, entomologist at ITM. “Some areas, like Schelle and Boom, are already heavily infested, while in others, such as Puurs-Sint-Amands and Wilrijk, the species has overwintered. This clearly illustrates how tiger mosquitoes are hitching rides with passenger and freight traffic, allowing them to spread rapidly along major transport routes."

Comparison between the banded mosquito (1), the common house mosquito (2) and the Asian tiger mosquito (3), and a five eurocent coin.

Citizen involvement is more crucial than ever

The results of three years monitoring clearly show that the tiger mosquito is not only entering and spreading more and more in Belgium, but it is also starting to establish within the country.

Since the start of the MEMO+ project, the tiger mosquito has been reported in a total of 36 locations across 35 municipalities via the citizen science platform, with new locations detected every year. On top of that, tiger mosquitoes have also been detected in seven out of the eight parking lots actively monitored in 2022 and 2023. Increased engagement from both citizens and local authorities in surveillance and prevention is therefore essential to properly monitor the situation and control the further establishment of the species in Belgium. Citizens can take preventive measures themselves by removing breeding sites containing stagnant water in their garden. Recommendations on how to do it are available on MosquitoSurveillance.be.

Javiera Rebolledo Romero, Sciensano researcher, says: "Given the growing number of reports from citizens about tiger mosquito sightings, it's likely that this species may already be present in more places of Belgium than previously confirmed. We encourage the public to stay attentive: if you're spending time in your garden or terrace during the day and notice mosquito activity, if they are small, black and with white stripes in the hind leg, take a closer look. There's a chance it could be a tiger mosquito"

The full public report on the 2024 surveillance is available at https://mosquitosurveillance.be/reports.

MEMO+

The monitoring of exotic mosquitoes in Belgium is continuously gaining social relevance. The MEMO+ project rests on two pillars:

Active detection of exotic mosquitoes at the known import locations
Calling on citizens to spot and report mosquitoes

More info

The Asian tiger mosquito (Aedes albopictus) is a small stinging mosquito with a white stripe on the back of its head and back, five white stripes on the hind legs with all-white tips, and a white tip of the palps (= mouth parts near the proboscis)

How to report a tiger mosquito?

If you think you’ve spotted this small black-and-white striped mosquito, you can take a photo and upload it to the online surveillance platform, available at MosquitoSurveillance.be or via the app (available on Android and iOS).

Report a tiger mosquito