Drones, sterile males, traps... How cities are fighting tiger mosquitoes

Municipalities are fighting back to get rid of the tiger mosquito , which is increasingly present in France. This week, the town of Brive, in Corrèze, began releasing mosquitoes to disrupt the tiger mosquito's breeding season. Eleven million sterile males will be released by the end of summer.

These males, raised on an insect farm and then sterilized as adults by irradiating their DNA, are capable of mating but cannot produce offspring. The females, who are the only ones to sting, mate with them and end up laying empty eggs. They are deceived, without the use of chemicals and without harm to the environment.

For this to be effective, ten sterile mosquitoes must be released for every single wild mosquito. The method has been tested in Réunion Island with promising results. Brive is the first city in mainland France to experiment with it.

Other municipalities are opting for different methods. In the Paris suburbs, the town of Levallois-Perret attracts and traps females in a box that emits an odor similar to that of human sweat. In Hyères , in the Var region, and in several municipalities in Charente-Maritime, drones are being used to identify and treat stagnant water points in inaccessible areas.

In Occitanie, around Montpellier, and also in the Camargue, specialized brigades are working to spray larvicides. This diversity of methods illustrates the difficulty faced by communities affected by this small, 5-millimeter pest.

Cities are stepping up their efforts as tiger mosquitoes reappear with the warmer temperatures, which now regularly exceed 15 degrees. Eggs laid the previous year are hatching. Alerts are increasing on dedicated apps and portals. The French National Agency for Health Security is tracking reports.

The tiger mosquito, which originates from Asia, is black and striped with white. This insect colonized Europe through international trade. It was first detected in mainland France in 2004 in the Alpes-Maritimes region.

Its aggressiveness and stealth make it a formidable pest, especially since it is active throughout the day and often flies low, near the ankles and calves. The tiger mosquito also poses a health risk, as it carries diseases.

Global warming is accelerating its progression and according to ANSES, the risk of a dengue, chikungunya or Zika epidemic in metropolitan France is now considered "quite high" for the next five years.

Municipalities aren't the only ones who can take action. The French can also help combat tiger mosquitoes, which lay their eggs in very small amounts of water. It's recommended to empty containers such as flower pots or buckets, cover water tanks, and maintain gutters.

Some town halls distribute gutter screens or offer home diagnostics. Trimming tall grass and picking up fallen fruit can also help limit the presence of mosquitoes.