In Pessac, a citizens’ brigade is mobilizing against the proliferation of the tiger mosquito

Almost 1 p.m., in a family garden in Pessac (Gironde). The three little boys hurry around the swimming pool: it is finally lunchtime. On the laid table, the plate of melon sits next to the cutlery, the carafe of water and… a bowl of steaming coffee bean powder lit with a blowtorch. This year, Alain no longer wants to be surprised by the tiger mosquito and this natural repellent has proven effective so far. To complete and perfect his arsenal against the summer’s number one enemy, the 65-year-old retiree received a visit this morning from Jean-Marc Albert, a neighbor in the neighborhood and ambassador for the city’s fight against the tiger mosquito.

Faced with the proliferation of the insect and the numerous complaints from the population, the town hall launched, in 2021, a fleet of ambassadors whose aim is to inform and provide advice to residents. Three years after the launch of the project, seventy volunteers bear this honorary title. All have followed training provided by the town hall, in partnership with the Bordeaux metropolitan area mosquito control center: life cycle and reproduction of the mosquito, specificities and health risks, advice to be given to eliminate all places likely to accommodate the larvae, etc.

Everyone concerned

Originally from Southeast Asia, the five-millimeter insect, recognizable by its black dress with white stripes, has colonized in a few years all twenty-eight municipalities of Bordeaux Métropole as well as 78 of the 96 French metropolitan departments. Responsible for nuisances, particularly for its itchy bites, the tiger mosquito is also a potential vector of viral diseases such as dengue fever, chikungunya or zika. To reproduce, the female lays her eggs on the surface of stagnant water. However, 80% of larval breeding sites are located on private properties 1. To limit proliferation, everyone has a role to play. During its life, the mosquito only moves a few meters. If it is present in your garden, “there is a good chance that it has taken up residence there or in the nearby neighborhood. That’s for sure!” assures Christophe Courtin, head of the Mosquito Control Center.

Jean-Marc, a retired telecommunications worker and a “pure” Bordeaux native, as he likes to point out, began a door-to-door campaign last summer in about twenty neighboring houses. Since then, he has been visiting people’s homes on request: “I understood that the effort had to be collective. I don’t impose anything, I simply explain why one action is preferable to another,” explains this grandfather of four grandchildren. A welcome pedagogy for an insect that is still too little known.

During her life, the female can lay five times one hundred and fifty eggs. These are “extremely robust”, says Christophe Courtin: they can stay dry and keep their explosive capacity for several months, even years, while waiting to hatch in a few drops of water. “A storm is enough to raise the water level in the receptacles and cause an explosion of hatchings”, adds the specialist.

Mosquito aperitifs

This morning, Alain’s tour of the garden proved constructive. With his keen eye, Jean-Marc noted all the places likely to be a larval breeding ground. Each time, a solution is proposed: line the saucer of the basil pot with sand, put a mosquito net on the rainwater collector or the gutter inspection window… “A multitude of solutions exist 2confides Fatima Chehrouri, in charge of participatory projects for the city. The town hall cannot be everywhere, but thanks to the ambassadors, a horizontal exchange is set up. It is very important to inform and break down preconceived ideas.

Worried by the mention of tropical diseases, residents can thus be reassured. By biting a sick person, the mosquito can transmit it to a healthy person, but no case of this type of so-called “native” transmission has been noted in Gironde to date by the Regional Health Agency. At the end of the visit, Alain and Jean-Marc greet each other warmly. Not far from there, “mosquito aperitifs” have been organized by other ambassadors. A good way to share information and ensure that the tiger mosquito is no longer part of the game.

1) According to the Bordeaux metropolitan area mosquito control center.

2) All the advice to limit the proliferation of the tiger mosquito on the site: bit.ly/ars-aquitaine-moustique-tigre