France heatwave cuts mosquito activity, scientists explain

An unprecedented heatwave that swept France this summer brought record‑high temperatures and prolonged drought. Social‑media users noted the near absence of mosquito bites, with one posting, “Even the mosquitoes have abandoned us under this heat,” and another commenting, “There are no mosquitoes at the moment.”

Entomologists explain that mosquitoes cannot regulate their body temperature. Extreme heat drives them to seek shelter in vegetation to avoid dehydration, reducing their activity. The lack of humidity further hampers survival; temperatures above 35 °C make it difficult for larvae to develop, and dry conditions prevent egg‑laying. The common mosquito is especially affected, while the tiger mosquito can lay eggs that remain viable for months in dry conditions, waiting for rain to trigger hatching.

Experts warn that once cooler, wetter weather returns, mosquito populations—especially the resilient tiger mosquito—could rebound quickly, potentially increasing the risk of bites and vector‑borne diseases later in the season.