Moustique tigre

 

Moustique tigre

The tiger mosquito (genus Aedes) is one of the most feared Invasive species An exotic species that is becoming harmful to local biodiversity. . In just a few decades, this mosquito has succeeded in colonizing the world thanks to globalization and its marked ecological adaptability.

Originating in the tropical forests of Southeast Asia, it has since spread throughout the world. It arrived in Europe in 1979 via Albania, and conquered the continents of North and South America during the 1980s. In the 1990s, it was also found in Africa and Italy. It is now present throughout southern Europe, where several populations have already established themselves, notably around the Mediterranean Sea. It is also moving northwards. Populations are now established in northern France and Germany, just 150 km from Belgium. To visualize the current distribution of the tiger mosquito in Europe, consult the map from the European Centre for Disease Prevention and Control (ECDC).                                                                                                                                                                                                        The tiger mosquito was first observed in Belgium in 2000, entering via the import of used tires. Since 2013, the tiger mosquito has been found in our country almost every year, introduced via the trade in used tires or "lucky bamboo". Since 2018, tiger mosquitoes have also been imported into Belgium via cars or trucks from neighboring countries. Despite these repeated sightings, the tiger mosquito has so far failed to establish itself in our country.
 

What is the reproductive cycle of the mosquito ?

The tiger mosquito needs stagnant water to reproduce. The female lays her eggs on a solid surface (inside a pot, for example) above or next to water. Once the eggs come into contact with the water, they hatch and the mosquito continues to develop in the water. Originally, the tiger mosquito used natural nesting places to lay its eggs, such as tree holes or rock hollows containing stagnant water in tropical forests. Now that the tiger mosquito has spread globally, it has adapted well to urban environments and also lays its eggs in artificial breeding grounds such as used tires, barrels, buckets, gutters, flower pots or any other type of external reservoir containing water.

The active season for tiger mosquitoes in temperate climates begins around late April or early May and lasts until October or early November. Rainfall during these seasons provides them with a wide range of sites in which to lay their eggs, and warmer temperatures favour the development of their population.
Tiger mosquito development lasts between 7 and 30 days, and adult mosquitoes can live for a month or more.

Oeufs Aedes albopictus  Larve Aedes albopictus  Nymphe Aedes albopictusAdulte Aedes albopictus

A highly adaptable species !

Although the tiger mosquito only flies 200 to 500 meters on its own, it is highly resistant to long journeys and can adapt to different environments. Other unique characteristics of the tiger mosquito have made it one of the most feared Invasive species An exotic species that is becoming harmful to local biodiversity. , including :

  • Tiger mosquito eggs are drought-resistant, surviving up to a year without water. 
  • The tiger mosquito has a varied diet: the female can feed on the blood of mammals (animal and human), reptiles, amphibians and birds.
  • It is able to thrive in a wide range of climates. However, this species favors warmer temperatures where the life cycle is completed more quickly and the female lives longer. 
  • In winter, these mosquitoes and their eggs hibernate and can survive in this state at low temperatures, which has favored their geographic expansion compared to other tropical species.

Why prevent the tiger mosquito ?

The greatest danger from tiger mosquitoes is that they are capable of transmitting various pathogens. Indeed, this species is one of the most important vectors of the dengue, Zika and chikungunya viruses, but can also transmit the West Nile virus. The tiger mosquito is also very aggressive when looking for food. They can be particularly insistent, and the nuisance they cause is sometimes such that people avoid certain places.

How to recognize a tiger mosquito ?

Ae albopictus Ae albopictus:The tiger mosquito is a small black mosquito generally between 4 and 5 millimeters long, but can reach up to 9 millimeters. It can be recognized by the white line on the back of its head and back (indicator 1), the five white stripes on its legs (indicator 3) and the all-white tip of the last section of its hind legs (indicator 2).

How to differentiate the tiger mosquito from other mosquitoes?

Culex pipiens annotated Culex pipiens: The common house mosquito (Culex pipiens) is a yellowish-brown mosquito native to Belgium and is about the same size as the tiger mosquito. Unlike the tiger mosquito, it has no specific patterns on its back (indicator 1) or stripes on its legs (indicator 2). The body of the house mosquito is rounded and has yellow stripes.
Cs annulata annotated Culiseta annulata: The large ringed mosquito (Culiseta annulata) is a larger mosquito native to Belgium. This mosquito is dark brown and also has stripes, mostly beige and brown, on both its abdomen (indicator 1) and legs. The last section of the hind legs is completely brown (indicator 2). In addition, this mosquito has wing spots (indicator 3). 
Ae japonicus annotated Ae japonicus: The Asian forest mosquito (Aedes japonicus) is slightly larger, and although it also has striped legs (indicator 1), it has only three white stripes (indicator 2) on its hind legs, and the last two sections are almost entirely black (indicator 3). It also has more complex patterns than the tiger mosquito on its back, but these are golden on a dark brown background (indicator 4).
Ae koreicus annotated Ae koreicus: The Aedes koreicus species is very similar to the Asian forest mosquito, but its hind legs may have 4 to 5 white stripes (indicator 1). The last section of the hind legs may be completely black or have a small white line (indicator 2).
Ae aegypti annotated

 

Ae aegypti: The tiger mosquito is sometimes confused with the yellow fever mosquito (Aedes aegypti). Although it also has striped legs (indicator 1), this mosquito has patterns resembling a lyre, the musical instrument, silvered on its black back (compared with the white line on the black back of the tiger mosquito) (indicator 2). However, it can be more difficult to recognize if it loses the scales on its back.