Tiger mosquitoes detected at nine locations in Belgium since May: a call for further vigilance!

Thanks to the active contribution of citizens, tiger mosquitoes have been encountered at nine different locations since 21 May 2024. There are six new locations: Boom, Humbeek, Ghent and Schelle in Flanders, Verviers in Wallonia and Sint-Joost-ten-Node in Brussels. In addition, tiger mosquitoes have been spotted again in Wilrijk, Kessel-Lo and Wolfsdonk. Reports of tiger mosquitoes in four of the six new locations were made during the first three months of the season, which is remarkable as most reports are normally made in August and September.

Overwintering confirmed

Besides the reports at the new locations, research was conducted on tiger mosquito survival in the winter, at the beginning of the mosquito season. This year, it was confirmed that they overwintered in three new locations: Ath, Puurs-Sint-Amands and Kessel-Lo. Together with last year's confirmations in Wilrijk and Lebbeke, there are now five locations in Belgium where the tiger mosquito can survive. This understanding of overwintering behaviour is essential for risk assessment and adapting control strategies against this invasive species.

According to Isra Deblauwe, entomologist at ITM, these results are not surprising. "In 2023, we collected larvae from gardens in each of these locations, indicating a growing tiger mosquito population. The unusually warm winter further stimulated the survival of eggs." Isra Deblauwe stresses the importance of citizen reports: "Although tiger mosquitoes probably overwintered in more places, we could only actively monitor a few selected locations due to limited resources. Therefore, we urge citizens to continue submitting reports in known locations as well. This will help us evaluate the survival of the tiger mosquito in the winter and map its spread."

The vital role of citizens

Together with Sciensano, we stress the importance of citizen alerts for monitoring the introduction and spread of tiger mosquitoes in Belgium. Each report allows researchers to quickly assess the situation and take action, if necessary, in affected areas. Citizens are encouraged to continue reporting potential tiger mosquito sightings through the MuggenSurveillance website and app (available for Android and Apple). In addition, it is essential to avoid stagnant water - an ideal breeding spot for mosquitoes - in one's own environment to prevent the survival and further spread of the tiger mosquito.

Javiera Rebolledo Romero, epidemiologist at Sciensano, says: "The involvement of citizens in tiger mosquito monitoring is very important. Their contribution has enabled timely detection of new locations with tiger mosquito activity. The large number of reports and sightings clearly show the important role of citizens in monitoring this invasive species in Belgium. We encourage everyone to remain vigilant and keep reporting sightings of tiger mosquitoes. Together, we can strengthen our efforts to slow down their settlement in Belgium as much as possible."