Insects active beyond autumn season

Insects such as wasps, tiger mosquitoes, and green stink bugs are remaining active well into autumn, beyond their usual seasonal patterns. This change is linked to climate change, which is affecting the natural rhythms that once dictated insect behavior.

Climate change disrupts insect rhythms

Insects used to follow a natural calendar, with life cycles synchronized to seasonal changes. However, climate change has made environmental signals like temperature, humidity, and light intensity inconsistent, disrupting these natural rhythms.

Extended insect activity period

David Giron, a research director at CNRS and an expert in insect biology, notes that many insects are now active beyond the traditional May to September timeframe. Some species remain active until late November, with Asian wasps showing signs of perpetual summer activity due to warmer temperatures.

Tiger mosquito activity spreads

The tiger mosquito, which is not typically suited for the local climate, is extending its activity period. As of October 17, nearly all of Metropolitan France showed the red level on the Vigilance Mosquitoes website, indicating the active presence of these invasive insects.

Green stink bugs surge in numbers

Green stink bugs are also exhibiting unusual behavior, with unusually high numbers observed this year. Their population surge is linked to favorable summer conditions, and Météo-France has confirmed that September 2023 was the hottest September ever recorded in France, with temperatures 3.5°C above seasonal norms.

Long-term implications of warming

David Giron suggests that if warming continues, some insects may be present year-round. However, the absence of a proper winter could lead to the extinction of species that rely on hibernation for reproduction, highlighting the broader impact of climate change on ecosystems.