Monitoring of exotic mosquitos in Belgium (MEMO+)

How did we proceed?

We set up mosquito traps at 23 possible import locations throughout Belgium. Import locations are possible places of entry through which exotic mosquitoes can enter our country, e.g., companies trading in second-hand tyres, garden centres, motorway car parks from southern neighbouring countries, ports and airports. We used different traps and methods to increase the chance of finding and capturing mosquitoes. We then identified the mosquitoes based on external features and used genetic analysis to confirm that identification. The Royal Belgian Institute of Natural Sciences placed the mosquitoes in their collection as a reference for further research. For data management, we used the VECMAP® application.

Three years of intensive monitoring

In total, we were able to capture more than 52,000 mosquitoes during the MEMO project. In the process, we found three new species native to Belgium and four species of exotic mosquitoes.

The tiger mosquito (Aedes albopictus) was found in seven different places in our country. Results confirmed that this species likes to travel with lucky bamboo and second-hand tyres. During our research, we also found eggs on motorway parking lots in the provinces of Luxembourg, Namur, Liège and West-Flanders. This means that tiger mosquitoes can enter our country via access roads from France and Germany. Therefore, Belgians travelling by car through countries where the mosquito is established can unwittingly bring these unwanted passengers with them. It was the first time this species reached Belgium in this manner.

We found the Asian forest mosquito (Aedes japonicus) in Namur, on the German border in Eupen and in the area of Maasmechelen. The observation in Eupen is related to established populations of the Asian forest mosquito just across the border of Germany.

The Korean bush mosquito (Aedes koreicus) was already spotted in Belgium in 2008 and has since then established itself in the Maasmechelen area. However, the population is small and does not cause any nuisance.

We found an African malaria mosquito (nopheles pharoensis) at the airport in Liège. However, the chances of survival of this mosquito in Belgium are slim, as the temperate climate is not suitable for this species.

Mosquito monitoring, prevention and control are indispensable

Throughout the MEMO project, we spotted exotic mosquitoes (including the tiger mosquito) in several places in our country. The occurrence of a few tiger mosquitoes in Belgium does not imply an immediate major virus outbreak. However, if the mosquito is able to establish itself and therefore increase its population, the risk of local virus transmission increases as well. These results prove once again the importance of monitoring exotic mosquitoes and its subsequent prevention and control of the population in Belgium.

The 3 year MEMO project was financed by the Flemish, Walloon and Brussels governments and the FPS Health, Food Chain Safety and Environment within the framework of the National Environmental Health Action Plan (NEHAP). ITM carried out the project in cooperation with the Royal Belgian Institute of Natural Sciences (KBIN) and the Barcoding Facility of Organisms and Tissues of Policy Concern (BopCo).

The monitoring of exotic mosquitoes in Belgium is continuously gaining social relevance. Our research shows that we should look beyond their known import locations. Based on these insights, 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

Active and passive monitoring

From May to October, we try to catch mosquitoes in car parks along motorways to detect the possible import of tiger mosquitoes.

At the same time, Sciensano is running the Mosquito Surveillance citizen platform, a platform that allows citizens to upload their own pictures of (possibly) tiger mosquitoes. This passive component allows researchers to discover the tiger mosquito throughout Belgium. Through a combination of passive and active monitoring, the team aims to quickly find the tiger mosquito and have it controlled. Are you wondering if you’ve spotted a tiger mosquito? Take a picture and upload it on the platform.

The MEMO+ project started in September 2021 with funding from:

• the Flemish, Walloon and Brussels governments,

• the FPS Health, Food Chain Safety and Environment within the framework of the National Environment and Health Action Plan (NEHAP).

ITM carries out the project in cooperation with Sciensano and the Barcoding Facility of Organisms and Tissues of Policy Concern (BopCo).