The Rise of the Asian Tiger Mosquito in Belgium

The potentially dangerous Asian tiger mosquito has been seen in multiple locations in Belgium. Here’s how to identify them and how to report a sighting.

Introduction to the Asian tiger mosquito

The Asian tiger mosquito (Aedes albopictus), has become a significant concern worldwide due to its rapid spread and its ability to transmit dangerous diseases. Originally from Southeast Asia, this small but aggressive mosquito is now found across many continents, including Europe, where its presence is growing. Understanding its identification, life history, and the health risks it poses is essential for controlling its spread and protecting public health.

Recognizing the striped invader

The Asian tiger mosquito is distinct and relatively easy to identify:

• Size: This mosquito is smaller than the “everyday” (Culex) mosquito, measuring about 2-10 mm in length.

• Appearance: The Asian tiger mosquito is black with silvery-white markings. It has a single silver-white stripe from its head down the center of its back, as well as striped black and white legs. These bold markings give it the “tiger” moniker.

• Behavior: Unlike many other mosquitoes that are active during dawn and dusk, the Asian tiger mosquito is an aggressive daytime biter. It is particularly active in shaded areas, and its bite can be painful.

• Habitat: The Asian tiger mosquito is highly adaptable and can thrive in both urban and rural environments. It breeds in stagnant water, which can accumulate in small containers, plant saucers, discarded tires, and other similar objects.

The lifecycle of Aedes albopictus

The lifecycle of the Asian tiger mosquito involves four stages: egg, larva, pupa, and adult.

• Eggs: Female mosquitoes lay eggs just above the waterline in containers that can hold water. The eggs can survive desiccation (drying out) for several months, making them resilient and difficult to eradicate.
• Larvae and pupae: Once the eggs are submerged in water, they hatch into larvae within a few days. The larvae, known as “wigglers,” feed on microorganisms in the water. They then develop into pupae, a transitional stage before emerging as adults. The entire process from egg to adult can take as little as 7-10 days in warm conditions.
• Adults: After emerging, adult mosquitoes mate, and females soon seek out blood meals to nourish their eggs. They typically live for 2-4 weeks, during which they can lay several batches of eggs.

Where the tiger mosquito calls home

The Asian tiger mosquito originated in the tropical and subtropical forests of Southeast Asia. It was primarily found in countries like India, Indonesia, and the Philippines. In these regions, its population was kept in check by natural predators and environmental conditions.

Rapidly expanding into Europe

The Asian tiger mosquito began expanding its range in the late 20th century, largely due to international trade and travel. It first appeared in Europe in the 1970s, with confirmed sightings in Albania. Since then, it has spread across much of southern Europe, including Italy, Spain, France, and Greece, and has most recently been reported in parts of Germany, the Netherlands, and Belgium.

The mosquito’s spread in Europe has been aided by the transportation of goods, especially used tires and plants, which can harbor its eggs. Climate change has also played a role, as warmer temperatures allow the mosquito to survive in regions previously too cold for its survival.

The Asian tiger mosquito in Belgium

According to the Sciensano National Health Institute of Belgium, there have been 13 confirmed reports of tiger mosquitoes in nine different locations across Belgium since the start of 2024: Boom, Humbeek, Ghent, Schelle, Wilrijk, Kessel-Lo and Wolfsdonk in Flanders; Verviers in Wallonia; and Saint-Josse-ten-Noode in Brussels.

Of course, these are just the mosquitoes that have been reported; without a doubt the tiger mosquito is present in many more locations across Belgium but has not been spotted elsewhere yet.

Viruses potentially carried by the Asian tiger mosquito

One of the most concerning aspects of the Asian tiger mosquito is its ability to transmit a variety of viruses, posing a significant threat to public health:

• Dengue Fever: Aedes albopictus is a known vector for dengue fever, a potentially severe viral infection that can cause high fever, severe headache, pain behind the eyes, joint and muscle pain, rash, and mild bleeding. In severe cases, dengue can lead to hemorrhagic fever, which can be fatal.
• Chikungunya: This virus causes fever and severe joint pain, often debilitating those infected for weeks or even months. While not typically fatal, chikungunya can lead to chronic pain and long-term disability.
• Zika virus: The mosquito can also carry the Zika virus, which gained global attention for its association with severe birth defects, including microcephaly, in babies born to infected mothers.
• West Nile virus: Although primarily transmitted by the Culex species, the Asian tiger mosquito can also carry West Nile virus, which can cause neurological diseases in severe cases.

Strategies to control the tiger mosquito

Controlling the spread of the tiger mosquito involves various approaches:

• Source reduction: The most effective method to control the mosquito population is to eliminate breeding sites. This involves regularly emptying containers that collect water, covering water storage containers, and properly disposing of tires and other debris that can hold water.
• Chemical control: In areas where the mosquito population is high, insecticides may be used to kill adult mosquitoes or larvae. However, this method can have environmental impacts and should be used cautiously.
• Biological control: Introducing natural predators, such as certain species of fish or bacteria that target mosquito larvae, can help reduce the population. Additionally, research is ongoing into genetically modified mosquitoes that are less capable of transmitting viruses or that produce offspring with a reduced chance of survival.
• Public awareness: Education campaigns are crucial in helping the public understand the importance of preventing mosquito breeding in their communities. This includes promoting the use of mosquito repellent, wearing long sleeves and pants, and using screens on windows and doors.

How to report a sighting of an Asian tiger mosquito in Belgium

Sciensano has a dedicated website with lots of information on the tiger mosquito and the possibility to report your observation. It’s available in Dutch – Muggen Surveillance – and French – Surveillance Moustiques – although both can be auto-translated into English or another language. You are recommended to take a photograph of your mosquito and submit it along with the location. Sciensano will then be able to confirm if it is a tiger mosquito or not.

Conclusion: A global challenge requiring local solutions

The Asian tiger mosquito, with its striking appearance and aggressive behavior, is more than just a nuisance – it’s a carrier of potentially deadly diseases. As this species continues to expand its range, particularly in Europe, coordinated efforts at the local, national, and international levels are essential to mitigate the threats it poses. By staying informed and taking proactive measures, we can protect ourselves and our communities from this global invader.

Of course, the tiger mosquito is not the only potentially harmful invader that has encroached into Belgium in recent years. I covered the rise of the Asian hornet in Belgium two years ago – and it is continually growing in numbers and proving extremely harmful to native honeybees. I have also written about the appearance of invasive termites and raccoons in Belgium.

Any comments or questions on the Asian tiger mosquito in Belgium, feel free to contact me.

Denzil Walton

I created Discovering Belgium in 2011 to share the country’s hidden stories, fascinating places, and remarkable people. Through articles, photography, and audio walks, I share discoveries that reveal Belgium beyond the obvious. Hope you enjoy this site.