From Wednesday August 31 to Thursday September 1, 2022 night, one district of Prive and another district of Malemart carried out insecticide treatment to prevent the spread of the tiger mosquito-borne disease. We don’t know if it’s dengue fever, chikungunya or Zika, but a carrier person visited both of these places, according to the New Aquitaine regional health agency.
An exceptional nocturnal insecticide treatment took place in Brive and Malemart (Cores) to kill tiger mosquitoes.
Residents of these neighborhoods will be quiet for about a week. “The insecticide does not kill the larvae, it does not kill the eggs that give birth to a new generation of tiger mosquitoes in a few days”, notes Delphine Binet, head of the agency of Altopictus, which is mandated by the ARS to carry out the treatment.
ARS also emphasizes the exceptional nature of the system. “Insecticide not only kills mosquitoes but can also create resistance. It is already in some foreign territories,” says Delphine Binet.
In a city: Mechanical struggle and little effect
However, today it is a dream to imagine a garden, balcony or terrace in Prive or Malemart without tiger mosquitoes. Since the arrival of Brive in 2017 and Malemort in 2020, the mechanical fighting by public authorities (emptying cups, cleaning sewers and manholes, water reserves, etc.) has so far had no effect.
A larvicide will be tested in Prive (Cores) to combat the proliferation of tiger mosquitoes
However, “the best fight is to cut off the water,” assures medical entomologist Charles Jeanin, who has worked on the tiger mosquito for fifteen years for EID Méditerranée. This inter-sectoral agreement was created sixty years ago to control mosquitoes from the Mediterranean coast.
“The whole building hides invisible spaces that serve as breeding grounds. When we saw him arrive in Nice, at first, we were a bit arrogant. Today, except for Australia, no country in the world can protect itself from it.
The tiger mosquito has entered the “top ten” of the planet’s invasive species.
In the meeting: Release of sterile mosquitoes
However, “everyone is looking for solutions” to eliminate or reduce the population of tiger mosquitoes, which have prevented Korez residents from enjoying the outdoors this summer.
One of the more promising ways is to release sterile male mosquitoes. They thus mate with barren wild women. A ten-hectare trial was carried out in the summer of 2021, in the town of Prates-les-Les (Herald). Publications of this type have been taking place on Reunion Island for ten years. Experiments are also underway in Germany and Italy.
Three questions to better understand and combat the tiger mosquito, a summer nightmare in Korea
“There are four more or less controversial ways to render a mosquito sterile, the entomologist notes. The ones used in Prades-le-Lez came from Italy. They were made sterile using ionizing rays and then put to sleep for transport to Montpellier. “A hell of a logistics.
In New Caledonia: An interesting bacterium
Researchers also strongly believe in a bacterium called “Wolbachia.” Carrier males fertilize females that lay immature eggs. “This type of bacteria is injected into the Aedes aegypti mosquito.A relative of the tiger mosquito, Editor’s Note) also affects dengue fever. A project is underway in New Caledonia, where researchers are seeing less spread of the disease,” adds the scientist.
In Florida: Genetically modified mosquitoes
And then there are the more controversial methods. “US company Oxitec has been approved to release genetically modified Aedes aegypti mosquitoes in the Florida Keys. This transgenic species is dependent on an antibiotic and if the larvae are not present, they will not develop. But imagine that it is able to accidentally reproduce itself…”, slips Charles Jeanin. Finally, we can make the mosquito sterile thanks to molecular biology, “CRISPR Cas9 allows scientists to modify this molecular scissor gene. But ethical questions arise. »
In South America: Sterile insect release has proven itself
According to Charles Jeanne, the sterile insect method has already proven itself in other species, “crop insects or cattle-killing flies in South America”. However, he has some reservations: “For the mosquito, the path will be long, as the effectiveness has not been proven in large areas. So it is necessary to rely on multiple complementary methods. In short, everywhere in the world, we are far from ending the cruelty of summer.