Mosquitoes are already back in France – see areas most affected
Widespread hatchings reported in several coastal and eastern areas after an exceptionally wet and mild winter
Authorities stress that while the winter species currently active are regarded as a nuisance they are not known to transmit disease, unlike the larger Tiger mosquito, which is not implicated in this early wave
X-One Photo SM/Shutterstock
Mosquitoes have returned to parts of France weeks before spring, with widespread hatchings reported in several coastal and eastern areas after an exceptionally wet and mild winter.
Forecaster Météo-France said the country experienced 40 consecutive days of rain, with accumulations of 260-460mm in some areas.
February 2026 ranks among the three mildest since 1930, creating favourable conditions for early larval development.
According to the Entente interdépartementale pour la démoustication du littoral méditerranéen (EID), larvae were detected across nearly 6,000 hectares in January and February, compared with 2,900 hectares over the same period in 2025.
Mediterranean wetlands worst hit
The highest concentrations are in wetlands of the Mediterranean coast.
In Bouches-du-Rhône, reports are centred around the Etang de Berre and the marshes near the mouth of the Grand Rhône in the Camargue.
Large expanses of temporarily flooded land have remained waterlogged since December, allowing extensive hatchings of the winter saltmarsh mosquito, Aedes detritus.
Along the Aude coastline, including around Narbonne and lagoon areas, similar conditions have led to larvae being found across wide surfaces of inundated marshland.
Repeated marine winds and coastal surges have prolonged submersion in some low-lying zones.
Parts of Provence more broadly, including wooded and semi-urban areas within several kilometres of wetlands, have also seen adult mosquitoes dispersing inland from breeding sites.
Beyond the Mediterranean, anti-mosquito agencies report activity in parts of the Grand Est, where persistent rainfall has left standing water in rural and peri-urban areas.
Some areas have also recorded Culex pipiens, the common house mosquito, which develops in stagnant water and typically bites at night.
Treatment operations began earlier than usual, with larvicide applied on hundreds of hectares in February. However, saturated soils and poor flying conditions have complicated both ground and aerial interventions.
Authorities stress that while the winter species currently active are regarded as a nuisance they are not known to transmit disease, unlike the larger Tiger mosquito (Aedes albopictus), which is not implicated in this early wave.
Experts caution that it is too early to predict how the 2026 summer mosquito season will develop, as this will depend largely on spring rainfall and temperatures.
