On Monday 30 July 2018, Luxembourg’s Ministry of Health was informed that a population of the Japanese mosquito Aedes japonicus has been detected on private property in the town of Stolzembourg (municipality of Putscheid), on the Our river just north of Vianden in Luxembourg.

This first appearance of the Japanese mosquito in the Grand Duchy has been confirmed by the National Museum of Natural History (MNHN), following a genetic analysis of mosquitoes taken.

According to information received, this is an isolated incident. The Japanese mosquito moves little and does not travel more than a few tens of metres around its birthplace. Nevertheless, the German authorities (on the Stolzembourg border) have also been informed.

In the coming days, the Luxembourg authorities, with the support of a Swiss expert, will carry out the assessment of the situation at the location, as well as the implementation of a prevention plan and a monitoring, surveillance and eradication system. Training of relevant staff is also planned.

Eradication would be done without insecticides, but above all by eliminating potential habitats. Thus, the search for larvae is most effective, but adult traps can be used: gravid female traps with water / infusion of dead leaves or CO2 traps.

Asiam native species

Aedes japonicus is an invasive insect native to Asia. It is a large dark brown mosquito (10-12 mm) with characteristic white patches on the legs and along the abdomen, as well as 5 longitudinal golden strips on the thorax.

To date, the Japanese mosquito is the only exotic mosquito to have been detected in Luxembourg. However, it has already been detected in other European countries, notably in the province of Namur (Belgium), North Rhine-Westphalia and Hesse (Germany), and in Bas-Rhin, Haut-Rhin and Vosges (France).

What are the risks of the Japanese mosquito?

Japanese mosquitoes identified in Stolzembourg are unlikely to pose a health risk and are generally not carriers of viruses that are harmful to human and animal health. Their bites, though slightly more painful, should not be treated differently than those of native/local mosquitoes.

Unlike local mosquitoes, which usually bite at night and inside our homes, the Japanese mosquito stings especially during the day and in gardens or wooded areas.
To avoid mosquito bites, wearing loose, long, covering clothes and applying mosquito repellents are the most effective preventative measures.

How to avoid the proliferation of mosquitoes at home?

Mosquitoes (Japanese or not) lay their eggs at the edges of small volumes of stagnant water, rich in organic matter and devoid of natural predators (breeding sites or nesting sites). They particularly like the water that accumulates in saucers, flowerpots, clogged gutters and old tires. Thanks to their fast larval development (from 10 to 20 days), they can colonise very ephemeral habitats. Vigilance at all times, by draining stagnant water and removal of any object that may become a container of water, is necessary to guard against it.