The Council of State addressed a case on Monday regarding measures taken against tiger mosquitoes. These exotic mosquitoes can transmit serious diseases. Therefore, we do not want them here, but according to experts, we are going to lose the battle against the insect.
“It is a matter of time, then we will lose the battle and then they are simply here,” says mosquito expert Bart Knols. Tiger mosquitoes can transmit tropical diseases such as dengue, chikungunya, and zika. Vaccinations are available for dengue and chikungunya, but currently, these are only given to travelers.
The most common symptoms in people with dengue are severe headache behind the eyes, high fever, vomiting, and coughing. In the case of chikungunya, it often involves fever, painful joints, and sometimes a rash.
In addition to the diseases they can transmit, the annoying thing about tiger mosquitoes is that they bite during the day. “If a mosquito bites at night, then you place a screen or lie under a mosquito net and then you are protected,” says Knols. That doesn’t work during the day. “Then you go somewhere on a terrace to drink a cappuccino and you get caught.”
Tiger mosquitoes are not yet established in the Netherlands. The Netherlands Food and Consumer Product Safety Authority (NVWA) is the authority that tries to stop the mosquitoes. “To date, the NVWA has always managed to get local outbreaks under control,” says Knols. The first tiger mosquito was discovered in 2005. After that, the numbers increased.
“2023 was really a peak year,” says mosquito researcher Tessa Visser of Wageningen University & Research. At that time, 150 reports were made. In 2024, there were 106 finds. This year, there have been 25 observations so far.
“If you look at the broader picture within Europe, the situation becomes a bit more anxious,” says Visser. In the countries around us, the tiger mosquito has already established itself. For example, the map below shows that there are tiger mosquitoes just across the border in Belgium and Germany. “We are, as it were, being enclosed from the south.”
Vacationers Take Mosquitoes With Them
“Originally, it was a problem for tire importers and importers of bamboo plants,” says Knols. But now the problem is much broader. “It’s really about the Dutch public taking the mosquitoes with them,” Visser adds. Tiger mosquitoes hitchhike with people returning from vacation from countries where the insects have already established themselves, such as France, Spain, and Italy.
“Those mosquitoes lay eggs in someone’s garden and then we have an outbreak in the middle of a residential area,” according to Knols. “The European Union has tackled this whole problem far too late. And these animals don’t stop at the border.”
Therefore, there will come a moment when fighting is no longer useful. Visser estimates that it will be in three to five years. “But having that mosquito here does not yet mean that we also have the viruses that such a mosquito can transmit.”
In addition to a mosquito, there must also be people who have the disease in order to transmit viruses, and the two must come together “in a longer warm period,” Visser emphasizes. “The temperature is important for the mosquito, but also for the virus.”