The engine starts to whine, like that of a brush cutter. The agent slings his sprayer weighing around fifteen kg over his shoulder and walks through the steep alleys. A colleague guides him, map in hand, with large arm movements. White overalls from head to toe, respiratory mask on the face, noise-cancelling headphones in the ears… Their profile contrasts with the bucolic setting of the small town of Boulbon, near Avignon (Vaucluse).
Only headlamps and the full Moon provide some light. The church bell rings four times: it is the middle of the night. The enemy is called Aedes albopictus, the tiger mosquito which nests in vegetated corners.
“It is not a miracle product, nor is it trivial”
The operation was decided after the detection among the 1,500 inhabitants of several cases of dengue fever, a disease transmitted by this formidable insect. Actions of this kind, the Mediterranean Interdepartmental Mosquito Control Agreement (EID) carries out “two to three per week” at the request of the regional health agency, breathes Lionel Chanaud, who directs the operation, as he gets out of the car. Several missions have also taken place in recent weeks in Île-de-France, which the tiger mosquito has gradually invaded in recent years.
The team officiating this night at the end of September in Boulbon is divided into two groups of two agents, guided by a manager. Mosquito control takes place either on foot or in a pick-up with the sprayer which “spits” liquid from the rear of the vehicle. The product used is an insecticide, deltamethrin. It kills tiger mosquitoes, but it also risks damaging the environment, which environmentalists regularly denounce.
“It is not a miracle product, nor harmless, and it does not differentiate between small insects, but it is the same type of product as all those used in other areas, but much less powerful. We use 1 g of active ingredient to treat 1 ha, compared to 10 g for 1 ha in agriculture,” assures Lionel Chanaud. He himself ended up putting on his suit to clear a private garden inaccessible by pick-up.
“It’s the least bad solution, because it’s the only family of products approved in France,” adds Gregory L’Ambert, head of the public health division at the EID. To limit the risks of harming the fauna and flora, watercourses and organic cultivation plots, identified in advance, are avoided. “There is no water here, we can go there,” whispers an agent while examining an underground mouth with the light of his smartphone.
Residents had been warned during the preceding days, at least by message in mailboxes. They were instructed that night not to leave their homes, not to leave the windows open, and to bring in their laundry and pets.
But as we follow an agent at work, a dog starts barking. “The owner didn’t respond when I came by yesterday, and he obviously hadn’t received the information. But I reassured him, there is no risk for his dog,” says the operator, taking off his white coat, which is then thrown into a special bin.
At dawn, the smells have evaporated, and the village begins to regain a little life. The people of Boulbonnais welcomed this operation with kindness. “If it’s to protect the population, then so much the better,” summarizes Thierry, 56 years old and living here “forever”, while walking his two dogs. “It’s very good to do that. This summer, we kept getting eaten by mosquitoes, even during the day,” says the manager of the tobacco bar overlooking the central square.
The reactions are not always so welcoming. “One day, a person told us that she had had dengue fever, that she had not felt anything, and that she did not want us to treat her garden,” recalls Lionel Chanaud. In Saintes (Charente-Maritime), night mosquito control planned for the beginning of September was even canceled. Demonstrators gathered in the middle of the night to say “no to insecticides” and denounce the use of deltamethrin. Opponents also mobilized for the same reasons, Monday September 25, in Maisons-Alfort (Val-de-Marne).
“They are recalcitrant!” » grumbles Gérard, 76, sitting on the terrace of the main café in Boulbon. Dengue fever, “it can cause a high fever,” repeats several times this former farmer, born and still living a few dozen meters away. At 4 a.m., he was not sleeping when he heard “a huge noise.”
A few hours later, only the “Warning: mosquito treatment” stickers on certain mailboxes make visible what happened during the night. Grégory L’Ambert assures us: “To date, we have never seen a case of dengue appear after an operation. »