Residents of Provence and the Hérault region of France are experiencing an unusual surge in mosquito activity despite the ongoing winter months. Reports of mosquito bites are increasing, with some residents feeling as though summer has arrived three months early. This unexpected development raises concerns about potential public health implications as warmer temperatures can lead to increased disease transmission.
The early mosquito activity isn’t limited to marshy areas; it’s also being reported in residential neighborhoods and even cemeteries, stretching from the Mediterranean coast inland. Several species are already present, including the marsh mosquito and the tiger mosquito, even as nighttime temperatures occasionally dip near freezing.
Mosquitoes in Winter: A Incredibly Early Awakening on the Mediterranean Coast
On February 26, a tiger mosquito larva was discovered in a vase on a grave in the cemetery of Pérols, near Montpellier – nearly two weeks earlier than typically observed. “It’s really very early; egg hatching usually starts around mid-March,” explained Yannick Simonin, a professor of virology, in Sud Ouest. Marsh mosquitoes are also actively biting along the coast.
According to EID Méditerranée, this winter has been “rich and exceptional” in terms of rainfall, with two months of precipitation equaling that of a typically dry year. This has resulted in thousands of hectares of marshes and lagoons remaining continuously flooded, providing an ideal environment for larvae to thrive.
Aedes detritus, Tiger Mosquito, Culex: Which Mosquitoes are Biting and What are the Risks?
The initial wave of activity primarily involves Aedes detritus, commonly known as the marsh mosquito, a species typical of coastal brackish water zones. Their larvae benefit from the standing water left by the rains, and the adults can then travel several kilometers towards wooded or urban areas. “Unlike tigers, they fly very well and can travel several kilometers. As soon as you go out in Montpellier, you get bitten!” said Guillaume Lacour, an entomologist at Altopictus.
Tiger mosquito (Aedes albopictus) eggs remain attached to the walls of containers, awaiting favorable conditions. “The end of diapause depends mainly on temperature, and the average temperature in February in the Hérault region was +3.2 °C higher than the seasonal norms,” explained entomologist Guillaume Lacour. “Tiger mosquitoes should expose us to vector-borne diseases as early as the end of March, much earlier than usual,” warned Yannick Simonin. Mosquitoes of the Culex genus, which hibernate as adults, are also becoming active with the milder temperatures and can transmit West Nile virus, which can cause severe neurological complications, particularly in the elderly.
Exceptional Rainfall, Mild Winter: Why is the Invasion Starting Now and How Should We Respond?
The abundance of standing water provides a breeding ground for mosquitoes. EID Méditerranée reports that nearly 6,000 hectares of wetlands are already infested along the Provençal coast, and February 2026 ranks among the warmest Februarys since 1930. The cold weather has not played its usual role as a natural deterrent.
“It’s impossible, at this stage, to deduce what will happen next,” cautioned Jean-Claude Mouret, head of the coordination unit at EID Méditerranée, as quoted by La Provence.
For tiger mosquitoes, the focus should be around the home. “Now is the time for human action to be crucial,” emphasized virologist Yannick Simonin. He recommends eliminating all standing water, as “even a simple thimbleful is enough to nourish the larvae.” Simple steps, repeated after each rainfall, can make a significant difference:
- Regularly empty pot saucers and buckets.
- Cover or empty rainwater harvesting tanks.
- Change the water in vases frequently, including those in cemeteries.
