Picture of tiger mosquito leads to the finding of another exotic mosquito

Published on: 
Thursday, July 28, 2022
Last updated on 28-7-2022 by Cassandre Dugailliez

More than 200 people have already contributed to the monitoring of exotic mosquitoes 

After the report of a tiger mosquito (Aedes albopictus) on the MosquitoSurveillance website, entomologists from the Institute of Tropical Medicine (ITM) in Antwerp and epidemiologists from Sciensano went to inspect Maasmechelen. They did not find the tiger mosquito, but they did find the Asian bush mosquito (Aedes japonicus), another exotic species. The presence of this mosquito is less worrying, but also an indication of the increasing introduction of exotic mosquitoes in Belgium. ITM and Sciensano encourage everyone to keep sending in photos of possible tiger mosquitoes via the website.

A resident of Maasmechelen recently spotted a mosquito that looked different from the common house mosquito. After checking the MosquitoSurveillance website, the size, colours and back legs of the specimen looked suspiciously like those of a tiger mosquito, so the resident uploaded a photo. After analysing the photo, Sciensano and ITM deployed a field team to set traps and collect mosquito larvae to confirm the presence of the tiger mosquito. However, during the field investigation, the researchers found no tiger mosquito, but rather the larvae of the Asian bush mosquito (Aedes japonicus). In the past the Asian bush mosquito has been found in Belgium, but never at this location. This mosquito has been found before on the other side of the river Maas in the Netherlands. 

From identifying a mosquito in a photo to field research

The discovery of this exotic mosquito is an example of successful citizen science, in which citizens, Sciensano and the ITG each have a contribution to make. Javiera Rebolledo, Sciensano project leader of citizen surveillance explains: “Although we did not find the tiger mosquito, this case shows that the MosquitoSurveillance platform works and that citizens play an important role and make a major contribution in the passive monitoring of exotic mosquitoes in Belgium.ITM entomologist Wim Van Bortel added: “Based on a report of a tiger mosquito, we set our traps to actively look for and confirm its presence. Since we found no trace of a tiger mosquito, its eggs or larvae, we believe it was a one-time introduction. Therefore, the species probably does not have a population in this area. Nevertheless, the combination of passive monitoring and active trapping appears to be successful.

Monitoring of exotic mosquitoes in Belgium

The monitoring of exotic mosquitoes is important to determine their presence in time. The respective authorities can then intervene at an early stage to prevent the establishment of these mosquitoes in Belgium. If exotic mosquito species, such as the tiger mosquito, were to establish themselves here, local transmission could occur when a person infected with the dengue, zika or chikungunya virus returns from holiday and is bitten by this mosquito in Belgium.

It is clear that citizen participation can really make a difference here. Anyone who thinks they have seen a tiger mosquito can take a photo of it and upload it via the website https://muggensurveillance.be/. If a photo is taken, ITM and Sciensano will quickly take the necessary steps.


  • Sciensano for the citizen surveillance plateform: press@sciensano.be, +32 2 642 54 20
  • ITM for the active surveillance: adams@itg.be, +32 477 45 88 38

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