In a significant ecological development, scientists have confirmed the presence of mosquitoes in Iceland, a country long celebrated for its absence of these insects. On October 16, 2025, Björn Hjaltason, a resident of Kjós in West Iceland, discovered three mosquitoes in his garden and reported them to the Icelandic Institute of Natural History. Entomologist Matthías Alfreðsson identified the specimens as Culiseta annulata, a cold-tolerant species prevalent in northern Europe. This marks the first recorded instance of mosquitoes found outdoors on Icelandic soil, distinct from prior isolated cases of specimens arriving via air travel.
The discovery challenges Iceland’s unique status as a mosquito-free region, attributed to its oceanic climate with frequent freeze-thaw cycles that disrupt mosquito breeding, coupled with geographic isolation. The specimens, including a female and a male with distinctive feathery antennae, were verified through analysis by the Icelandic Institute of Natural History. Climate change, with Iceland’s temperatures rising approximately 2°F over the past two decades, is likely facilitating the establishment of new insect species, including over 200 recorded since the 21st century began.
This finding follows the 2015 arrival of louse flies (Hippoboscidae), signaling a potential trend of invasive species adapting to Iceland’s warming environment. While Culiseta annulata is not a major disease vector, its presence raises concerns about ecological shifts and the potential for other mosquito species to follow. Researchers note that Iceland’s changing climate may increasingly support such invasions, altering its historically inhospitable conditions for mosquitoes.
Ongoing monitoring by the Icelandic Institute of Natural History will be critical to assess whether Culiseta annulata has established a viable population or if this remains an isolated incident. Future studies may focus on modeling climate-driven ecological changes and their implications for Iceland’s biodiversity, providing valuable data for global research on invasive species dynamics.
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